SES light on. (Need to pass emissions)

[jbizel]

My SES light has been on for about a year now. I had it scanned at the Local Auto-Zone and it reads that there is a small emissions leak. Ive had my car into a shop on about 3 different occasions and they cannot find the leak. My tags are now expired and I need to do an emissions test. My SES light is not on all the time though. it comes and goes. Is there a way that I can disable the light or do something so it doesnt show the SES light being on? Can I just take out the bulb? or will the emissions place still know it should be on? So im basically asking........What can I do to pass emissions? I'm pretty sure it will pass all the tests but its just the SES light being on. what should I do?

[BNaylor]

In most states you will fail the emissions test if the SES/CEL light is on. The tester will know something is not right because the equipment used will look for emissions readiness indicators not being set and most likely see the stored DTC code(s).

Post the specific DTC code for further assistance.

[taillight]

Have you tryed replacing the gas cap ?

[BNaylor]

If he is getting a small leak DTC which is P0442 it is very seldom if ever a problem with a loose or bad gas cap. That normally gives you a P0440 which is a large leak detected.

See link below posted for helpful info on evaporative emissions related problems:

Click here

Old relevant post history:

Click here

[jbizel]

Originally Posted by BNaylor

If he is getting a small leak DTC which is P0442 it is very seldom if ever a problem with a loose or bad gas cap.

The Code I was getting was the P0442

Originally Posted by taillight

Have you tryed replacing the gas cap?

Yes I have tried the Gas Cap. That was the first thing I did after I saw that it was a small emissions leak.

So you dont think it would work if I disconnect the battery and then took it up there after I reconnect it ? I have disconnected the battery before and the reconnected it and the light usually stays off for about a week. Would that work or will it show that somethings funky?

Also. are there any stop leak remidies for the emissions system? Like how radiators and A?C systems have a "Stop Leak" solution?

[taillight]

It just might take that long to have the right conditions to run that test again. There are no stop leaks , you have to find the leak.

[BNaylor]

I agree. You'll have to find the leak. The problem with the P0442 DTC is the emissions readiness flag (IM status) will not set until all evaporative emissions tests pass which may take a few drive cycles. Not sure about the OP's state but in Texas you will fail the test which for '96 and up odb-ii cars consists of hooking up a scanner at the ALDL port and after that they connect another fixture to the gas tank at the filler neck for further evaporative emissions testing.

[jbizel]

Does anyone know where to find a diagram on the emissions system? I have no idea where to search for the leak. I do not know anything about emission systems.

[richtazz]

Your best bet is to take it to a garage that has a smoke machine. They unhook one of the vapor lines, and pump smoke in. where it comes out is where the leak is.

[BNaylor]

I agree with Rich. This is a complex issue if you have no knowledge of evaporative emissions systems. There are components such as the purge solenoid, vent solenoid, the lines, charcoal cannister and the gas tank since it has a pressure sensor. A bad fuel pump pod to gas tank o-ring seal can cause P0442 to set.