Help, my 2009 XLR won't pass smog.

[RodneyIE]

I've brought my vehicle to a local mechanic and a Cadillac dealer to determine why it won't pass smog, but neither could give me an answer.

There is some minor lower damage from scrapping on speed bumps.

Both mechanics estimated it would be about $4K to be able to get to the area and diagnosis it, does that seem right/fair?

Thanks

[Bruce Nunnally]

are there any diagnostic trouble codes (DTCs)?  Does it show 'ready for emissions'?

[RodneyIE]

No.  I think on most cars, the repair would be routine, but the mechanics are saying the reason it is so expensive is because of the difficulty getting to the issue.  They said they would have to remove the transmission, or some other major component to have access.  The mechanics also thought it could be vacuum leak related.  They already replaced the 02 sensor, but that didn't help.

[Bruce Nunnally]

That is not an input I would expect.  Can you retrieve the DTC codes to determine what the actual problem might be?

Did the dealer or mechanic actually tell you what they think is wrong?

[RodneyIE]

I will take it back to the dealer or Certified mechanic, and try and get a written diagnosis/estimate.  Neither of them mentioned DTC, but I just Googled it, and it makes sense.  Thank you.

[Bruce Nunnally]

For a car to pass smog, it has to be ready -- if you have disconnected the battery recently for example, it will need to drive for 50-100 miles to get emissions ready.

Failure causes can be bad O2 sensors, bad catalytic converter, or generally running poorly or misfiring and so not burning cleanly.  if the engine is running smoothly, and your check engine light is not on, but it is failing emissions, it is likely something subtle.  I would have expected the emissions test to show what failed as a clue.

[Logan]

What state / city are you in?

Most tests these days are plugging into the cars system and checking for codes and system status. With no codes and nothing pending the car passes.

I cannot imagine anyone would still be probing the exhaust.

 

That said....most state testing stations are contracted out to companies....huge tax revenue source for states.

 

 

 

[RodneyIE]

Hi Logan,

I'm in San Diego, California.  If you know of a shop in my area to bring it to I would appreciate it.  I don't know the technical terms, but the DTC, or other codes indicated a possible vacuum leak, and displayed some other unknown numbers that were way off according to the mechanics.   I grabbed the two attached photos from a YouTube video, to try and point out approximately where the problem may be coming from, indicated by the red arrows.  The green circle where the exhaust connects would be easy to remove, but according to the mechanic, removing the other side of the exhaust that goes up into the engine compartment is very difficult and expensive to remove.  Ideally, if the exhaust was completely removed, giving a clean view and access, the mechanic is confident that the repair would be fairly routine and reasonable.  It's the access to the upper exhaust that is complicating the repair.  I hope that makes sense?  Thank you.

[Logan]

Nothing really there except the catalytic converter and the exhaust pipe. That may explain the O2 sensor. I think all the EVAP lines are out at the sides of the car. 

If the SES lamp stays off after a 100-150 miles or so after clearing codes..... The system is ok. 

Sounds like they look at a scan tool and kind of make it up as they go. Most data on a scan tool would be Greek to most folks....sounds like they are really trying to figure out how deep your pockets are. 

In Tennessee.....they just connect a system and check for codes.....no codes and if your readiness monitors are ok you pass. All drive thru....no hoist...no visual inspection. 

 

If the SES lamp is on.....there should be codes. Sounds like it would certainly be worth your time investing in a $100 cheapo OBDII scan tool. 

[RodneyIE]

Yes, CA is very strict.

Thank you.