Fail Smog Test

Chevy Tracker 2000 Fails Smog Test 155,000 miles on it

My tail pipe emissions pass the California Smog Test but 2 lights come on say now 2 shops I have brought the car to and so they must report me as a gross violator! And I am one of the many hippies who got these air standards passed hmmmmf!

One light is the oxygen sensor and the other is the EGR [Exhaust Gas Re-circulation] Sensor. The Service Engine Soon light has been on and I am told by DMV and owner’s manual that this is enough to trigger a smog violation. My manual tells me a non-tightened gas cap, bad gas with low octane, wet electrical system or low charged battery may set this light off.

Right before the test, I had filled full the tank with an off brand cheap gas. Yesterday, I drove the car up Interstate HWY 5 from Sacramento to Chico round trip while having burned enough of the cheap gas to displace it with Chevron Techron with 91 octane and detergent.

I have also put 2 oz of CA40G - a fuel additive that sponsors the Ed Schultz show.

Still, my Service Engine Soon light is on.

Questions- are the 2 lights the shop is seeing -lights that I can see? Is my Service Engine Soon light one of the lights they are seeing?

Advice given to me was that shop installed a new battery- [i had never put a new one in the 5 years I owned it- and I bought it as 2 year old previouly leased car with 10,000 miles on it - Chevy Tracker 2000 2.0 litre]. Also fuel injection service and new air filter. We decided I would re-fuel with good quality gas.

I hardly drive the car and wonder if car is having these problems because I always have used the cheapest gas possible and that the car has been sitting most of the time for now 2 years. [I work online from out of my home and only take the car to the food coop once or twice a week.]

Thank you so much for any ideas you might have on how to get these lights off. The shop’s next step they feel is to diagnose why the lights are on or if the lights/ sensors are broken. I have until the beginning of April to take care of all of this.

I teach and I am now already up to 500 dollars. There is a low income program to help pay from the State of California, but I make too much money for it! - which doesn’t even pay off the student loans…until my death it seems…there are Gold Sheild Stations and Test only stations- I don’t know how these differ from my mechanic. I do feel that I like my mechanic and they are reputable- though they do not specialize in smog tests. Should I take the car to a third dealer?

A swag would be that replacing the oxygen sensor(s), and using a cleaner on the egr valve, and the passages to and from it, may do the trick. Things happen. There isn’t always a recognizable cause.

Don’t fill your tank up all the way!!! Stop at the first click. many drivers try to get that last quart in an screw up the evapoarive control system and have the CEL come on.

It would be good to provide the actual error codes, like P0123.

If you need this time to pass right away I would hold off putting all kinds of stuff in the tank. That might trigger a sensor. I suspect part of the problem may be low octane gas if your owner’s manual specifies high test. Buying too low an octane is false economy.

As someone noted, don’t top off the tank. That can set things off and may even damage it. Stop filling when it first clicks off.

I think there is a bit of confusion. The Service Engine Soon light is on because of at least one trouble code the ECM has posted. I believe the shop is seeing two codes on the code scanner they have, not two lights. Under your locations’ laws, they have to report the problem with the trouble codes. This is because the ECM system that uses ODB-II (On Board Diagnostics 2) system monitors the truck for it’s own emissions. A failure in the emissions system will set a code, or multiple codes. The system codes should also point to the problem.

It would be nice to know the exact codes, like P0132, but the shop says the codes are for the O2 sensor and EGR. There are many codes that cover both of these. The most common EGR problem is ‘Low Flow Detected’, meaning a problem in the EGR hoses, like debris build up plugging up the hoses. Not uncommon for an 8 year old truck with 155K miles on it. The O2 sensor may need to be replaced.

Your mechanic should be able to run the codes and fix the problems. Not knowing the exact codes, I can’t begin to offer a reasonable cost estimate. But, if the problems are fixed, and the light goes out, then it passes emissions.