SpencerT

95 ls400

I could always smell the cats but only if I had the windows down and accelerated hard.

Now I can smell them with the windows up with mild acceleration or when climbing a hill.
Gas mileage has also decreased slightly.

Is this just because its cold out and the engine is getting more gas or is there another issue?
I havent noticed them glow either.

cobalt91

Do you mean like sulfer?

RA40

iTrader: (6)

Check for any codes. SImple starting possibilities in my mind: O2 sensors, bad plug/s and ignition wires. When was the last tune-up? Plugs, wires, caps and rotors? When was the last time the air filter was checked/replaced?

SpencerT

Yes like sulfer.
That lovely fart smell our cats make.

SpencerT

Havent checked codes yet. I always have a cel due to an exhuast leak at the cat flange, but ill check them.

I did plugs and wires 7500 miles ago.
caps and rotors are probably due.
air filter I checked about 1000 miles ago and it was perfect.

Lavrishevo

iTrader: (1)

We have a winner!

That code is putting your ECU in a preset or "limp" mode that does affect performance and mileage. Need to get that fixed.

SpencerT

Ive had that code for over 2 years. It was like that when I bought the car.
I really doubt that it is my problem.

LScowboyLS

I agree with the "limp" mode diagnosis, especially if you are seeing performance degradation

and many things can cause it, all of the things RA40 mentioned, as well as many others such as the ECTS and the MAF

or even

wait....

wait for it.....

the ECU caps!

SpencerT

I dont think its in limp mode. She still has plent of power, I can just smell the cats when I accelerate.
ects reads within normal range.
havent checked maf but I assume its good too.

Ill read the codes tomorrow and go from there

RA40

iTrader: (6)

The EFI system is compensating for the erroneous exhaust reading. You are lucky to have not burned up the cats during this time. If this were a CA car, high odds that your EGR would be plugged and would it have failed emissions testing.

Lavrishevo

iTrader: (1)

For over 2 years!

I'm sure your code is 420 or 430. You have been blowing inaccurate fuel to air ratio through your exhaust for 2 years now... All 4 02 sensors need to be working good for the ECU to do its job. I bet your cats have really taken a beating. When the ecu detects this problem in runs in a closed loop instead of real time monitoring. Probably running really rich.

cobalt91

could ya post the codes? With out them we're guessing. Usually the smell means that the mixure is rich. It could be anything from a vacume leak to bad caps in the ecu. More info please.

SpencerT

it is a ca car
Ill check for new codes tomorrow but as far as I know it only sends a 420 or 430. whichever is the passenger side cat below efficiency code.

Dont hate on me because I have tried to fix the leak. I replaced the gasket but the flanges were so rusted that it still leaked afterward.

LScowboyLS

actually, this is only half-true

a quick O2 sensor primer:

we need to differentiate between the two pre-cat O2 sensors and the two post-cat O2 sensors - the ones that the ECU looks to in order to make on-the-fly calculations and adjustments, which affect how the car runs are the pre-cat O2 sensors, on the other hand, the post-cat O2 sensors are strictly there to be the emissions "tattletales", so to speak - it is the post-cat O2 sensor that is the reason you no longer have to sit in that long line in some cities like Phoenix, where during the early to mid 90's, we had to wait for them to physically hook up a big tube to the exhaust pipe and measure the exhaust vapors for particular contaminants - with the advent of the post-cat O2 sensor, the ECU just stores a "you have been naughty" code! - lol

If you don't care about the environment (like you should), and your area doesn't have mandatory emission testing, you don't need the post-cat O2 sensors at all - you could hook up a set that were dead years ago and your car would run as good as new, but you would generate an ECU code, and on some cars an annoying CE light! (but even that is easily jimmied to show the ECU what it wants to see to not throw a tattletale code)

I kept my post-cat O2 sensors, because not only am I an environmental type, but I also like an early warning that something is amiss! (but I certainly didn't have to keep them in good shape, I live in Alabama, they never heard of an emissions test here.........ugh!)

PS - your 430 code - (bank 2 sensor 2) is the post-cat code for that side, which would jive with the sulfur smell and may be a bad cat or another issue causing bad emissions products that are below thresholds.

RA40

iTrader: (6)

It is fixable. Just don't want you to have to spend excessive money and cats are $. The EGR is a PITA because age makes the connecting pipes brittle. As LScowboyLS mentioned the pre-cat sensors are important for the EFI in determining the fuel ratios. Once you get this fixed, your car will drive so much better.