CEL emissions inspection question

"Chairman Kaga" (mike-mckinnon)
11/15/2013 at 10:26 • Filed to: None

My wife's '02 Camry has been consistently throwing a CEL for a fuel system evap leak. It's been to two shops on four separate occasions and no one can diagnose it. Smoke tests, sniffer tests, bench testing components, all kinds of methods. Yes, we replaced the gas cap. The last shop said they could replace the entire evap system for about $2,800. They both said it would not pass inspection though.

So if we reset the CEL, based on the comments form the mechanics I assume the test will still indicate the problem and that it's not resolved, thus resulting in a fail? Not clear on this. We can keep trying other shops until someone finds the problem, but we are NOT paying 3/4ths the value of the car to fix a problem that has zero impact on the way it drives, its safeness, or its performance.

DISCUSSION (18)

Arch Duke Maxyenko, Shit Talk Extraordinaire > Chairman Kaga
11/15/2013 at 10:28

My e36 has had that issue since I bought it, but fortunately Cincinnati has no emission testing!

PilotMan > Chairman Kaga
11/15/2013 at 10:30

Start replacing the sensors associated with the system.

Using your phone, download the Torque App that turns your phone into an OBDII scanner, buy a bluetooth OBDII plug that fits your car. You shouldn't spend more than $30 so you can read and clear your own codes.

Or reset the light for free at your local auto parts store then go trade in the Camry before the CEL returns.

offroadkarter > Chairman Kaga
11/15/2013 at 10:32

I generally refuse to work on imports so forgive me if this doesn't apply but

My friends 04 crown vic was throwing an EVAP code for "small leak", it turns out the charcoal canister filter that is in the evap lines was clogged, and I mean CLOGGED. I took the whole thing apart, cleaned the filter, put it back together and its been fine ever since.

Chairman Kaga > offroadkarter
11/15/2013 at 10:41

We have the "small leak" code too. That was my first guess based on my reading. But both shops pulled and bench tested the canister and the valves, which is no small or cheap job. We even replaced the valve that's the most frequent culprit. Light came back on within a month.

Chairman Kaga > PilotMan
11/15/2013 at 10:43

Advance Auto around the corner form the house does both for free. I just can't figure out if the ECU stores the faults so that the emissions tester can see the problem still exists? How would they know we had or had not fixed it though? I'm inclined to clear the code, have the car tested, and hope for the best.

offroadkarter > Chairman Kaga
11/15/2013 at 10:47

did you think to check the gas tank filler neck hose? I don't think that would show up on a smoke test

Chairman Kaga > offroadkarter
11/15/2013 at 11:03

I didn't on my own, but I think the first shop did a full inspection of the fuel system. There's no fuel smell though. Every once in a while there's some smoke from the exhaust that's pretty gassy. Maybe it is still the filter system? I mean, it could have been a bum part we installed, or maybe we just missed something. I probably need to take it to a shop that specializes in cars built after 1972, this time!

PilotMan > Chairman Kaga
11/15/2013 at 11:04

The scanner should clear the generic OBDII codes but your car's computer may retain more specific Toyota codes that only the dealer can clear.

But this issue should be cleared with just a standard scanner. The emissions station will require a complete reading to certify Emissions Readiness s/DTC. If your car can't complete the required readings then it won't be able to pass. Most cars need to be driven for 40-50 miles to complete the readings.

offroadkarter > Chairman Kaga
11/15/2013 at 11:16

I hate suggesting the dealer, but maybe the dealer...

EVAP system issues can just be a real bitch, but I'm sure you know this already!

offroadkarter > Chairman Kaga
11/15/2013 at 11:18

OH! Heres an idea. I'm not sure how it works on a toyota, but I'd check to see if you can do this..

On a Ford, the EVAP system will only initiate a test between 3/4 and 1/2 tank. If your state allows for 1 not ready system, reset the PCM so all the codes clear, keep the tank above 3/4 of a tank and let all the other emission systems relearn themselves to a ready state. This way you can pass with 1 not ready, the EVAP being the "not ready"

Chairman Kaga > PilotMan
11/15/2013 at 11:20

It usually takes several tanks of gas before the code is thrown again, so maybe we can skate by by clearing it and hoping for the best. The shop did say the CEL isn't tripped until the third fault, and that emissions testing would be aware of any codes prior to that third one, so probably better off clearing the codes then going right away to the testing center. Nefarious!

Chairman Kaga > offroadkarter
11/15/2013 at 11:21

That's worth exploring a bit more. I do know the CEL is only ever tripped toward the end of a tank. Thanks for that law skirting tip!

Wonder if a good old ECU reset wouldn't help thing, too? Pull the positive batter terminal, let it sit for a few hours, good to go. used to do that with my old Honda, for some reason or another.

offroadkarter > Chairman Kaga
11/15/2013 at 11:27

If the situation has been fixed and you reset the PCM, it won't trip the light again. But when it runs the test and it isn't fixed, the light will come back on.

PilotMan > Chairman Kaga
11/15/2013 at 11:34

It sounds like your Camry has graduated to old car status and joined many others with an unnecessary check engine light.

Union of Smog Techs of CA > Chairman Kaga
11/15/2013 at 13:48

California? The system is simple and easy to diagnose if the mechanic knows what they are doing. If everything tests ok, then what sensor is the ECM using to detect the code? It is possible that a component performance is close to triggering its own fault code and generating false codes in other systems. There is another way to look at scanner data called Mode 6, this is raw data that must be interpreted. Not all mechanics know how to find the OEM instructions for Mode 6 but if they can diagnosing is alot easier. If code sets at 999, but sensor is reading 998, performance is affected but computer is not compensating.

Union of Smog Techs of CA > Union of Smog Techs of CA
11/15/2013 at 13:51

Here are Toyota's own technical training manuals, EVAP is in there. Fun reading and very clear and concise. http://autoshop101.com/

It might not directly affect performance, but fuel is lost due to evaporation and there is possibility of vapor catching fire and tank implosion under certain EVAP failures.

Chairman Kaga > Union of Smog Techs of CA
11/15/2013 at 15:27

Travis County, Texas.

Thanks for the info. I'll study up!

Union of Smog Techs of CA > Chairman Kaga
11/15/2013 at 16:01

Your welcome. I have access to ALLDATA and IATN if you need further tech help.

Good Luck!