Grrrrrrrrrrrrr

[BiXLL]

My car just failed both mechanical and emissions inspection this morning. The mechanical was just tie rod ends that I have replaced all ready, but I am stumped on the emissions. The car is running smooth, getting 27 mpg city, and all seems right. According to the machine, I am way high on both Hydrocarbons and CO2!!!

I have changed plugs even though old ones are like new, air filter is 4 months old. I am running a can of SeaFoam injector cleaner through it now and we will see what happens.

Really caught me off guard, as I stay up with the maintenance on my cars!

[cmkelly]

Try some Dry Gas in the tank to help with the emissions numbers. That worked for me years ago. In NC they don't even do emissions testing on cars as old as ours. I think they do 1996 and later.

Good luck!

[john_93 vert]

We have had similar results several times ( six S13's in the family ) A lazy O2 sensor will throw the results and if that doesn't do it replacing the cat. will.

[Harman850T5]

I feel for you, In my county they just do a visual check for the emissions components and a gas cap test.

[GoinTopless240]

I'm guessing the O2 as well as the Cat. How many miles on this one BixLL? You replaced Inner and Outer Tie rods? Maybe the steering rack would be next or lower control arm bushings. I'm glad we don't have that here or my car would have to be a trailer queen...lol
Good luck

[BiXLL]

I'm guessing the O2 as well as the Cat. How many miles on this one BixLL? You replaced Inner and Outer Tie rods? Maybe the steering rack would be next or lower control arm bushings. I'm glad we don't have that here or my car would have to be a trailer queen...lol
Good luck

Its got 138,000 on it. I can't help but think that if it was the o2 sensor it would affect the way it runs???? I am starting to lean to the cat being bad myself.

I replaced outer tie rod ends, only 1 of them failed, but there was some movemnt in the other one so I changed it out as well.

[Loki]

27 city mpg holy wow...I struggle to get 20, although I admit I like to make it go vroom vroom

[GoinTopless240]

Man Loki.. mine goes vroom pssst and I'm getting 23-24.. still on stock tire and wheel combo?

Bixll the only reason I mentioned O2 was that if O2 is reading slightly off it may cause a slightly rich mixture and the CAT can't filter it all (especially if it is older) kinda a combination thought. The dry gas is a thought. Dry gas is like an alcohol in that it pulls the moisture out, just with the current 10% oxygenated mixture currently out there not sure if it will help or hurt. This new gas plays havoc with older cars. The faster burn rate of the oxygenated gas cause some pre-detonation, almost like retarding the timing = less complete burn and left over CO2 and HC's. If you can get some "non-ethyanol" gas and run a tank or two and swap out plugs it may eleminate the problem all together. 93 of course.. Emissions is no fun.. always hated when I lived up north..also hated "winter" gas, but I guess we got lucky enough to get it all year long now.

[BiXLL]

Well, I ran half a can of carb cleaner through the vacuum hose to the air box thing where the idle adjustment is, changed plugs, and ran a can of Seafoam though the gas tank. I just got back from the inspection station and not only did it not pass, the numbers were worse!

It is idling as smooth as silk, has no misses, runs great! No codes have been thrown, but the exhaust does have a strange smell to it. Not the rotten egg smell, but strange. I am at a loss once again, as if either the O2 sensors were bad or cat bad it show throw a check engine code????? I don't know where to go from here!

[BiXLL]

well guys, appearantly our 02 sensors can fail without throwing a code. I changed mine out and all numbers came in, car passed emissions inspection! I still do not understand how the performance was not effected though???

[GoinTopless240]

Good to hear your problem was sorted out. OBD I is a bit basic and can be fooled easily. If the O2 sensor failed, but continued to send a value that was within the ECU parameters-then no code. Basically the O2 wasn't really sniffing like it should, but was still telling ECU all was good (kinda like a plugged nose). Glad you got her feeling good again.

[biggie]

Yeah, have never known a bad O2 to throw a code in S13s.