Harbinger

So I just failed my 2nd TX emissions test. After the 1st one they gave me a list of things that could be causing the high emissions(since there are no codes being thrown). I seafoamed, changed the oil, changed the plugs(ran 100 miles before the test), cleaned the O2 sensors(no lights, just figured it would help - rear sensors only) and nearly ran the tank dry before putting a few gallons of Chevron in it for the test(I only use Chevron or Quik Trip anyway). On the retested the numbers WERE THE SAME OR WORSE!
HC 467 low speed 452 high speed
CO2 4.87 low speed 4.69 high speed
NOx 1089 low speed 1092 high speed

The shop is felling me that it has to be the cats at this point, but there is no way for me to check their integrity because the prior owner welded them to the Y pipe. Besides, this shop already gave me bad advice the 1st time. Any ideas?

My car is a 92 SC4 with 186,xxx on the clock. No engine mods. No smoke. Some valve tick from the left bank. Test performed with OD off, Trac off and PWR on.

chiken

Quick easy pass. Run tank almost empty, put about a half a gallon denatured alcohol and go take test. Fill tank with premium right after test and don't run the car hard on the alcohol. This is not the right way to pass and probably not legal but if you want to fudge it without dishing out cash for some cats its the cheapest way. (Note: the car will not run very great on the alcohol)

Harbinger

I think I'll give that a shot. With my gross polluter status I will have to run almost pure denatured alcohol to pass. Seems that my extremely high CO2 levels are pointing to a compression issue, resulting in me being pig rich and blowing the HC and NOx levels too. Looks like a rebuild is in my future.

One interesting note - when I was running down the tank(I had 1/2 a bottle of seafoam in about 1/4 tank of gas), the car smelled great - clean. The only think I could smell was the scent of fresh oil burining off where I has spilled some after it splashed out of the container. After putting about 4 gal of chevron in the tank there was a distinct change in the aroma of the exhaust. It became noticeably harsher and more bitter, although the performance of the car didn't suffer.

xxtoobsxx

iTrader: (4)

put up a pic of the results! the o2 reading will tell if its your cats. nox is your egr system, clean or replace. If they don't check timing retard it a bit...lol. Oh and new NON UNIVERSAL o2 sensors

c-low

iTrader: (1)

^^vehicle specific!

xxtoobsxx

iTrader: (4)

I had the same prob with my old sc...fixed mine

chiken

What kind of cats did the previous owner weld in? I dunno if it's the same part but I have an O2 sensor from a MKIV TT supra.

1slowsc

iTrader: (2)

My old honda failed smog with no cel. I used Iso-heat and it passed next try.

Harbinger

Believe it or not he welded the STOCK 22 y/o cats to the Y pipe. Most likely in an attempt to fix an exhaust leak(he gave me a bunch of exhaust gaskets when I bought the car). What I am planning to do is eliminate the 2 primary cats and run it straight from the stock headers into a new 6 and put one high flow cat in the 3rd cat location, keep the resonators and my top speeds. The only thing that I haven't worked out it how to eliminate 2 of the O2 sensors without throwing a code.

I will definitely post up the results as soon as possible.

Harbinger

I suspect if I had just gone straight to the inspection station with what I had in the tank without adding any additional fuel I would have passed.

Harbinger

***Cliff's notes because this was longer than expected:
*Running 1/2 gal petrol & 2 gal denatured alcohol yielded much better numbers on the roller, but still a fail. Shop possibly trying to coerce me into performing work with them.

*Running a 5:1 ratio petrol/DA yielded excellent results and a pass in the rev & idle test, with a shop fan blowing and the air filter partially moved out of the way.

*The SC is running great on this 5:1 mixture. It is said DA will corrode rubber & plastic over time, but is is safe to continue running this until I can afford a rebuild some many months down the line?

*I may or may not being going to jail/paying a fine for missing my appearance date due to the court closing early/procrastinating getting this done.


Picking up where we left off - After failing the prior time, the inspection location offered to have his mechanic look at & repair my vehicle and then retest, emphasizing that it is most likely the Cat(s) that have failed. Seems worthwhile to have someone look at the car and get another go around at the sniffer, when we typicaly only get 2. Being in a crunch I decided to go the denatured alcohol route based on the information provided here and what I was able to scrounge up on other boards. Seeing how I was in gross polluter status I figured it would take running on almost straight DA to pass.

This morning I ran out the crap Chevron gas(not all Chevron's are built the same, regardless of whether they are corporate stores or not). I literally drove around until the needle was below E and the Low Fuel indicator light came on the 1st time. Then I put 1/2 a gallon of Quik Trip in the tank drove 2 blocks away from the inspection location and put in 2 gallon of DA ($15 & change each from home depot). Drove around the parking lot about 10 times and then did a spirited 2 blocks. Left the car running while I chatted with the mechanic who had not been apprised of what was going on with my vehicle. I gave him a copy of the results and he came up with a list of things that I had already addressed, plus the cats. He kept urgin me to allow them to look at the cats, even though once they cut them off there would be no way to install anything since they do not perform any sort of welding at that location, so I would have been up a creek. i politely declined and asked them to perform the test. He put the SC on the rollers and all I could smell was the alcohol being burned, and figured that they would too since we were in pretty tight confines... but they seemed oblivious. Now everything except my NOx levels reduced. NOx levels actually increased, but the other levels did not reduce enough to allow me to pass overall.

Results:
HC high speed (1505 RPM) 328( improved but still 3x over) / HC low speed (1494 RPM) 286 (improved but 2x over)

CO2 High speed PASS (0.23) / CO2 Low speed(0.64 - just barely failed - passing is 0.62)

NOx High Speed 1665(way up) / NOx low speed 1447(way up)

Dilution % High speed 12.4 / Low speed 14.5

O2 High Speed 5.0 / 4.7 Low speed

At this point I'm just baffled, and now they're pushing me to go to another shop to have my cats done. I inquired if I could have the 2 primary cats eliminated, install a new, high flow cat in the current 3rd cat location and keep the resonators and mufflers and rconfigure the O2 sensors. Of course they said no, stating that I had to retain everything in a stock configuration, but if I spent enough fixing the issue it would be an automatic pass. This sent up red flags all over the place, so I took my paperwok and left. Figuring I had nothing to lose, I decided I would try another shop.

Pulling out of the location and attempting to accellerate I felt my 1st stumble, and I knew I had to dilute the mixuture asap. I stopped at Exxon, which I normally don't use, and put 10 gallons in the tank(without shutting off the engine - yes dangerous, but I didn't want to risk not being able to start). The SC merged into traffic and accellerated onto the highway brilliantly. There were no stutters, no hesitation, and it smelled "clean" again. Ended up wasting about an hour waiting on another shop that had an outrageous line(SC was running the entire time), and decided to head to a shop that is a little bit out of the way, but still in the same county. Well, their dyno was broken, so they sent me next door. Here is where things get interesting...

I figured if I was going to attempt to subvert the system, I might as well go all out. I turned my gauges back on( I normally run blacked out unless I'm in a school zone or in another situation where I absolutely need to know anything from the gauges. Otherwise I just drive by feel and sound). Anyway, the reasont that this is important is because after recently replacing my needles, my temp needle is a bit light(and the gas needle a bit heavy - easy to swap but I just haven't). This gave the impression that the car was running hot, but not overheating, so the shop put a fan in front & left it on for the test. Taking advantage of this I adjusted the air filter to allow approx 2" fresh air beneath it with the filter still technically in place in the box. Then I left the Trac on. I don't know if anyone else has experienced this, but the pror shop argued me up & down that my car was not RWD only because it kept attempting to crawl off of the rollers with the Trac enabled. One of the service techs even attempted to point out the components in the front on my vehicle that enabled it to enter AWD mode. I should have just let them be idiots and I probably would have passed the 1st time, but I was being super honest and turned the Trac off for them. So long story even longer, car is on the rollers at the new shop and tries to crawl off. "Oh this isn't just driven by one axle, we can't do the dyno, we have to do the Idle and Rev test". PERFECT, as this is the method by which everyone has passed using DA(that I've read about)

This time I passed with flying colors(with a 5:1 ratio of gas/DA:
HC High speed(2371 RPM) 151 / HC Low speed(690 RPM) 174

CO2 High Speed 1.04 / Low speed 0.31

NOx 0.00 both high speed and low speed

Dilution High Speed 14.0 / Low speed 13.8

O2 high speed 1.3 / Low speed 1.6

So if you're going to subvert the system, go all the way. As an aside, (after the fact - as in after I had passed) 3 things: 1 - This shop agreed to modify my exhaust however I want, without issue as soon as their welder comes back from vacation(in about 10 days). 2 - They guy knew I had failed the prior day, because he asked me about it(and I was honest), but apparently the shop had not uploaded the fail from the current day. 3 - My SC is running REALLY well with this 5:1 mixture. Normailly I only get just below 100 mi per 1/4 tank, and I've run about 120 mi and I'm just about at 1/4 with the mixture. Would it hurt to continue this?

chiken

Sounds extremely shady to me. I'm in Florida now and don't have to deal with emissions anymore but used to live in Colorado and had to deal with emissions on many levels. Without actually seeing your car and how things are running ect, I can't tell you exactly what is going on.

I don't know how your emissions are done there but it sounds like they are independantly owned shops which in my eyes throws up huge red flags. In colorado you would have to go to a state run testing facility where there are no automotive repairs being done, only a line of cars waiting to get on the rollers to be tested, usually 6 or 7 bays for testing. For Classic cars you could go to a seperate repair facility but they only do static idle and rev tests.

I would not doubt if your first shop's equipment wasn't reading correctly, possibly needs to be recalibrated? This may be on purpose to help them access more business or it could just be chance. I have personally run vehicles through with no cats running on less of a denatured solution than what you had run and passed with flying colors on the dyno. This is mainly because in theory it will not release hydrocarbons which is the main reason why you will fail especially with supposed bad cats which burn off excess hydrocarbons. It will make your NOx go up as you can see from your results. So running the solution that you were, you should have passed with flying colors easily unless possibly your fuel gauge is off and you really had a lot more fuel than you had thought.

Basic questions on your car, you sound like you pay very close attention to your car which is good so I assume you will know this. What kind of gas mileage have you been getting? Do you burn/lose any oil? If so how much per 1K miles? What other work do you have done to the car?

I would not run alcohol on a regular basis, it will take it's toll on your fuel system long term, it's just a quick fix. I would hold off on letting any shops make any repairs at this point, just take your pass and find a starting point with your car. If you really are failing that bad then it can bea ton of different things and could be very basic. The money they will most likely charge you for your "repairs" you could probably buy better quality parts and do it cheaper yourself or find another shop not taking advantage of people trying to pass emissions.

Supra Dr

iTrader: (14)

Although inept I don't think the shops were trying to rip you off. They were poorly trying
to explain a Waiver. In Pa if you fail you need to attempt to repair the issue. The repair needs
to directly relate the area of failure, ex high Nox - EGR system repair. After you spend more
150.00 in repairs & it still fails you will be issued a waiver for 1 year.

If you could post up the #'s & limits from the 1st test we maybe able to help narrow things down.

Harbinger

As it did to me, especially since the NOx levels went up each time. Coincidentally the. SC spent some time in Florida as there is a U of M decal stuck hardcore to the rear windscreen, there was a Jaguars decal on both front windows & a bunch of paraphanelia from both in the trunk. I've never runn the VIN, but the frame was straight, no signs of flood damage & it was a good deal so I wasn't worried about its history.

Anyway, no oil being burnt. Every bit of 5 qts came out in the last 2 changes(nov & earlier this week). Changed the plugs both times as well - using NGK platinum both times. Tips were in good shape, but I can't tell you about carbon deposits because the 1st set were probably original to the car and I seafoamed on the 2nd set. Gap is set at .034 because the idle is smoother and it feels stronger than when they were set at the .044. Wires are autozone special because I plan on upgrading & didn't want to spend a lot for a "throwaway" set, and once again the originals were original to the car. I've also cleaned(not replaced) the rear O2 sensors, replaced the caps, rotors and both coils. I only ever use chevron & quik trip unless I'm in a real bind(this is based off of using these exclusively on my dsm's and having a squeaky clean tank after 190k). I run a bottle of lucas oil through every 3rd tank. I average about 21 mpg with mostly highway driving at higher speeds(85-90mph as I travel during off hours). I know I'm running a tad rich with this set-up but I'm ok with that. Definitely doing a BFI after the results a couple days ago. Other than that, nothing else other than fluids changes that would affect driveability. In the next few weeks I will be doing a BFI and having my exhaust done(1 high flow cat instead of 3 stock cats, keping, but replacing the 2 upstream O2 sensors, and splicing the 2 downstream sensors together and extending the wires to take a single reading from the cat which will be located in the current 3rd cat location. I'll be keeping the resonators and top speed mufflers).

Unfortunately after each test he took the prior test results. I do know thst the NOx went up between the 1st & 2nd tests and skyrocketed between 2 & 3, which I posted. CO2 & HC remained stable between 1 & 2(high failure though), and both significantly dropped between 2 & 3. From what you've indicated, it seems like I need to disassemble and clean my EGR system. I've already made preliminary arrangements to take care of the cats(elimination of 2 & replacement of 1) and exhaust.

Here are the numbers that I haveGas cap passed every time, no engine lights, OD off, Pwr On each time)

Passing Test(Rev & hold only 0690 RPM low speed, 2371 RPM High speed, 10 gal petrol to 2ish Gal Denatured Alcohol, with a shop fan on & air filter partially removed, outside temp in the upper 40's, about 90 min since the failed test - heater off)
HC: Standard - 220 / Me: 174 low speed; Standard - 220/ Me: 151 high speed

CO2: Standard - 1.20 / Me: 0.31 low speed; Standard - 1.20 / Me: 1.04 high speed

O2% No Standard - 1.6 low speed / 1.3 high speed

NOx: 0.00 for both low speed & high speed

Dilution: Standard. - >6 / Me: 13.8 low speed; Standard - >6 Me: 14.0 high speed


3rd Test (2 gal DA/.5 Gal to maybe a gallon of petrol - 1494 RPM low speed @ 15mph & 1505 RPM @ 25MPH on the rollers, outside temp in the upper 40's, less than 15 miles driven, but thoroughly warmed up - heater off.)
HC: Standard - 112 / Me: 286 low speed; Standard - 108 / Me: 328 high speed

CO2: Standard - 0.62 / Me: 0.64 low speed; Standard - 0.60 / Me: 0.23 high speed

O2% No Standard - 4.7 low speed / 5.0 high speed

NOx: Standard - 829 / Me: 1447 low speed; Standard - 751 / Me: 1665 high speed

Dilution: Standard. - >6 / Me: 14.5 low speed; Standard - >6 Me: 12.4 high speed


2nd test(from above, after a general tune up & seafoam I assume the same rpm and mph on the rollers as the above test, but I cannot verify, outside temp in the upper 60s, just finished driving 120ish miles )

HC: Standard - 112 / Me: 467 low speed; Standard - 108 / Me: 452 high speed

CO2: Standard - 0.62 / Me: 4.87 low speed; Standard - 0.60 / Me: 4.69 high speed

Harbinger

Ok, so some of the 2nd test results got cut off:

O2% No Standard - 4.7 low speed / 5.0 high speed

NOx: Standard - 829 / Me: 1447 low speed; Standard - 751 / Me: 1665 high speed

Dilution: Standard. - >6 / Me: 14.5 low speed; Standard - >6 Me: 12.4 high speed