Hello-

I have an 05 TC and I just went for my first emissions test.

I have not had a check engine light come on since I installed my header 2 years ago. But I failed my emmissions test because a P0453 code came on when they turned the car on.

P0453 - Evaporative Emission Control System Pressure Sensor High Input

Can anyone tell me where to start in fixing this? Is it really 100% coincidence that the CEL came on when THEY started the car? Thanks!

 

There's a good chance that the code has been stored in the ECU for a long time, but it doesn't throw a CEL. If they had any testing equipment hooked up to the car, that could also have caused it.

First things first though: Clear the code, drive for a bit, and have the ECU checked again. If there is no code at that point then you may be able to take it back and pass the test. I'd suggest talking to the inspector first and allowing him/her to verify that there is no code without they're test equipment installed. They may give you a break, if it does pop up again.

Second: Check your warranty - in many cases, emisssions equipment has a longer warranty than the rest of the car. If you can get it fixed under warranty you may still have to put the stock exhaust manifold back on before you take it to the shop - and you should definitely have it on before getting the emissions inspection. If you don't have a catalytic converter installed, then you probably wouldn't have passed the emissions inspection anyways. It depends on what they look for during the inspection in MO. I'm not sure about MO, but some states don't just test for a universal baseline of emmisions, they actually test to see if the car still complies with the stock ULEV-rated emissions. They may also do a visual inspection to see if all the OE equipment is in place. Depending on what you have done to your car, taking it back to stock may be the only way you can pass the test.

Unfortunately, the code isn't very descriptive, which makes it pretty much impossible to troubleshoot without having it hooked up to a diagnostic system. I don't know where the evap. pressure sensor is installed or how it works. "High input" could mean high pressure or high voltage... "high voltage" could mean either high pressure or low pressure, depending on how the sensor works... there's just too many variables to take a guess at it.

If the code comes back after clearing it, you should probably put the stock manifold and cat back in, then clear the code again, then see if it comes back again. If it doesn't, then it was caused by the header. If it does, then you can get it checked out without any hassle.

Incidentally, this is a good example of why a lot of shops don't like working on modified engines... aftermarket parts - especially performance parts - add a lot more variables and difficulty to the troubleshooting process.

Good luck!
~Laken

 

Thanks for the reply~ I'll give everything you stated a shot over the coming week.

I passed everything except this code as they don't hook anything up to the exhaust is my understanding. They also didn't mention any of my aftermarket parts, header/intake

 

Quick update~ When I started the car today the CEL was gone. I did not reset it. Will it reappear if I get tested again?

 

not sure. i'd say take it to a local Autozone and have them check it with their code scanner. have them clear any and all codes if they can, then take it back to get tested for the emissions again...

hope this helps some!

 

I'm not 100% positive about the tC, but I know that a lot of vehicles will store a code like that, even when the CEL isn't on. You definitely need to have the ECU scanned to see if it's still stored in there. I suspect it is, and that it will show up in the emissions inspection again.

If a code scanner doesn't pick it up, then you should be fine to get the inspection again. If it does, I'd suggest referring to my previous post.

~Laken