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Loss of power, won't rev over 4k, high fuel consumption, hot catalytic, no codes.
For the past few weeks, I'm been searching and reading the forums. Been slowly getting suggestions and trying to figure out what the issue is from both friends and reading from here. Even had to take it to the shop once. First to explain as best as I could from the start.
Before I attempted to repair my car about a month ago, I started to notice issues while driving it the month or two prior. I didn't bother with it much and just drove my car to work and to the girl's house. I notice my car misfiring and feeling like it lose power going up hill. Felt like I was not using all my spark plugs. Finally use my Bluetooth obd2 scanner and it came out as this.
Before all this, I ignored an bank 1 sensor 1 o2 sensor for over a year. I don't know what happened to that code. I might have reset and refreshed it and got these while the o2 code was still waiting to pop up. I don't know. I did know I needed to replace that as well. Also, the VSC and traction lights came on.
If I remembered right, I think it was only 2 cylinder misfire. As I drove it just to get by and try to save money for the parts, I notice some more changes. I drive about 15 minutes to work and back. During the early part of commute to work or home, my car seems okay and seems to have power. Maybe because I'm in town and not cruising over 55mph. As I continue driving to work and back, I notice a loud hum coming from the front. Usually when I am driving home as home has a bit more hills to drive on compare to work. But I hear a hum when I try to speed up from a dead stop or go up hill to get up to speed. It would take longer to get up to speed but I also didn't want to step on the pedal all the way. One time I was almost home and I turned to my street. Car just kinda loss most power and didn't want to go forward. I had to rev up to 3.5k and drove with this loud hum just to get home. I figure I need to jump on this quick. Next few days, this never happened to the car. It still feel weak and was misfiring. The car made a hum at higher rpm. Just this part of not being able to go forward didn't happen and loosing power didn't happen. I should also mention that my car slowly started to lose miles per gallon. I use to get about 24mpg. Now it's dropped down to about 17. I looked at the dashboard display meter.
So I finally order parts. I figure I try fixing the misfiring. Ordered ngk iridium spark plugs, ngk wires, ngk boots, and a Fram air filter.
The coils were these. Not exactly oem. Just read some of the reviews and people said it works.
Search on DIY tutorials from here and was gonna change it out myself. Sucks that I had to remove the throttle body and intake manifold. So I did that but as I got into it, I see leaks. So I postponed and ordered valve cover gaskets. Put everything back and drove it until my other parts got here.
Felpro Valve cover gasket and manifold gasket arrived. Attempted this job again during the weekend. Swapped out and did everything. My motor was leaking oil. Had to clean up the spark plug holes before removing them using a spray body to suck up all the excess oil. After doing all that, I wiped whatever I could the best as I could.
Just throwing this out there if anyone is curious if something may be wrong. I end up braking some of the plastic pieces holding the wires. Also broke one clip of the ignition coil wire that connects to the coils. Once everything installed, put everything back and test it. The car revs better and doesn't have that misfiring or stutter of the car anymore. The misfiring codes are gone. The o2 sensor code is still there. I felt good.
Work day comes again. Same thing happens again but seems a lot worst. My loss of power and the car humming up front seems to come sooner than later before getting to work or back home. Drove it there and back and the next day I end up borrowing my dad's car. Still trying to figure out what it is now. Only CEL is still the bank 1 sensor 1 code. Getting frustrated.
So after more reading, researching, and asking friends, figure it might be the catalytic converter. So I thought I replace that. One week later got the new catalytic converter.
Brand - Pacesetter
It arrived and sent it to the shop to get it installed. Didn't have proper tools and it was getting way too cold up here in the Midwest. I also order the bank 1 sensor 1 Denso o2 sensor as well during this time. Told the mechanic to swap it out and install the new sensor. Total end up being another $350 because one of the old o2 sensor broke and they ordered a new one at $150 to replace it. Part of it was my fault as I didn't pick up their phone call so they just went and ordered it. But $150? I bought my Denso on Amazon for a little less than half that price. I just said screw it and paid. I wanted my car back and hope everything was okay... But it wasn't. The mechanic said he test drove it and it still doing the same and suggest the muffler is clogged from maybe the old catalytic converter going bad. Who knows if it was bad to begin with.
It took me 30 minutes to get home. At first getting out of the shop seems alright but the issue of loosing power and humming kicked in as I hit the hill. Getting up that hill took forever. I end up stopping 3-4 times to let my car cool off and to let traffic go. I turn off my car every everytime. What suppose to be a 10 minute drive home from the other side of town to the other end up being 30. Then as I finally got to the street before turning to mine, I just slowly cruise at around 15mph revving no more than 3.5k. It won't go past that now. I try going to neutral and it still won't rev pass that. Then I get home and parked. Notice a burn smell as I got out. Open the hood and it was red hot down there.
Probably have to end up buying a new one if this didn't fry it already.
Back to the forums and friends I go. This had become a pain and headache. What else could it be? Some friend say check my Maf. Did the pull the plug on the maf test and car shut off. Also sprayed it with some CRC Maf cleaner. Some friends said it could be a bad throttle body and I need to replace it. Some said it could be this TPS sensor. One said bent valves. Don't know exactly what valve he's talking about. Some said timing. Some said to recheck my spark plug wires.
So I end up checking again and notice something. Wet or oily cam gears in the front. Could timing have slipped? My cousin help changed this out back in early 2016. I bought a kit from ebay that includes the needed parts for timing replacement. I don't know but I do know if I have to take that apart, I need to spend more money on tools.
Anyone had a similar issue? Definitely in need of help as this is a damn headache. There isn't a check engine light anymore as well. VSC and traction are not lit on dash. Maybe I might have messed up or misplaced something during the first time I tried replacing spark plugs but ended up putting everything back together as I needed to do valve cover gasket as well. I don't know.
I also notice when I step the pedal all the way and it revs to 4k or now 3.5k, there is this noise. Doesn't sound metal. Not a banging noise or metal sound. Sounds more like plastic. Can't really describe it. Not knocking. Maybe flapping noise.
Clean your MAF sensor, I had a pretty similar situation with loss of power and hesitation caused by a dirty MAF sensor(ended up replacing with a new one)
I'm going to guess that headers glow because of heat (turbo exhausts do that under testing), clogged exhaust (unlikely, if it's after-cat), or dangerously lean. Try unbolting the exhaust after the cat, to see if the exhaust is clogged. After that... sounds like a lean situation, which would be air measurement (MAF).
We had an '00 Camry that had an air-measurement problem... left home for work, made it about 1/2-mile, and then it just wouldn't pull past idle. Put the car away for the week, then spent 3hrs during the weekend, testing everything. Finally turned out to be the vacuum line had blown off the MAF sensor... the car was always measuring 1 atmosphere, no matter how much/little air was being introduced to the throttle-body. Zip-tied it on, an no issues since.
Vacuum/pressure leaks are the worst things to debug.
Glowing cats typically means the engine is dumping fuel, or running really rich. It could mean bent or burnt valves, but I dont think that would be inconsistent like it sounds your issue is. My guess is a vaccuum leak of some kind or a bad/weak igniter. What codes are you currently getting?
Glowing cats typically means the engine is dumping fuel, or running really rich. It could mean bent or burnt valves, but I dont think that would be inconsistent like it sounds your issue is. My guess is a vaccuum leak of some kind or a bad/weak igniter. What codes are you currently getting?
Sorry for the long reply. Been busy and stressing out with this and the holidays here already.
Driving back from the shop usually takes about 10 minutes going through town but this day it took me 30 as I had to stop from time to time and letting traffic past me. I'm sure the car would have thrown another code at me by now but it didn't. No codes. Right now it's just parked with the throttle body off as I wanted if I messed up somewhere.
I am hoping it's just a vacuum leak but finding it might be the issue. I'm not too knowledgeable on taking apart my engine and checking the valves. So I hope I don't have to do that.
I should mention the car is bone stock. No upgrades. No turbo. No HP gaining. Just a daily driver with possibility of some future upgrade projects but mostly appearance.
If so, first, make sure you put the coil packs and plug wires back on in the correct order (if you need a visual reference and can't find one, I can take a pic of mine tomorrow). If that checks out fine, then test for spark on each plug. As for timing: you should find a small white timing mark on the front of each cam gear. They line up with those two little humps on the black metal shroud directly behind the gears when the engine is at top dead center. Try to line em up - you can do this by putting a breaker bar on the crank pulley and slowly rotating the engine until both timing marks are visible. If they don't line up, your timing is off.
Lastly, make sure the throttle body is sealed/seated properly when you reassemble it. Double check all sensors that could be loose or not fully seated.
If so, first, make sure you put the coil packs and plug wires back on in the correct order (if you need a visual reference and can't find one, I can take a pic of mine tomorrow). If that checks out fine, then test for spark on each plug. As for timing: you should find a small white timing mark on the front of each cam gear. They line up with those two little humps on the black metal shroud directly behind the gears when the engine is at top dead center. Try to line em up - you can do this by putting a breaker bar on the crank pulley and slowly rotating the engine until both timing marks are visible. If they don't line up, your timing is off.
Lastly, make sure the throttle body is sealed/seated properly when you reassemble it. Double check all sensors that could be loose or not fully seated.
Again sorry for the long response. Been really busy. As for the wire set up, this is how mine is. I believe it is right. I know I messed up when I didn't take a before picture. So I ended up looking for how to and pictures off the web.
The mechanic said he test drove it and it still doing the same and suggest the muffler is clogged from maybe the old catalytic converter going bad. Who knows if it was bad to begin with.
Yeah this was a guess probably not the issue...often happens when someone doesn't know the 2GS. Save yourself some time (and more money) and take it to a reputable Lexus indy...or better yet your closest Lexus dealer. Can't tell you how much the $140 dealer diagnostic fee has saved me over the years.
The coils were these. Not exactly oem. Just read some of the reviews and people said it works.
Btw, always use OEM parts! I can't tell you how many times on this board people have said they replaced parts and had to do it all over again because they weren't OEM.
In closing you have some work to do...first step, take it to someone who understands the car....next, don't buy parts until you know the issue.
11-19-17, 11:35 AM
Loss of power, won't rev over 4k, high fuel consumption, hot catalytic, no codes.
