RSRRacer

What could be likely causes of CEL if you install a cat back no muffler exhaust like euro pipe or sharky. Cats and o2 sensors in tact.

Do you need to plug or tie off vacuum line that used to activate sport mode for oem exhaust?

Thx

TRAKCAR

Should be no CEL at all?

996FLT6

Did u try resetting cel and see if it triggers again? Mike

Jenner

YES

CEL is probably triggered due to vacuum leak.

flyingpenguin

Why speculate on the cause of the CEL instead of getting the actual error code and be done with it? Autozone or Durametric. Pretty simple.

RSRRacer

Thanks for the responses.

I have been told I should just stick to driving and leave anything mechanical to someone else, and this is proof!

What would be the proper way to configure the sport button vacuum thingy when installing a the track exhust (no muffler but oem cats)

Should I just unplug the electrode that controls the valve?

Do the above, and ALSO plug all other outlets (the original hose and the metal valve by the electrode?

If someone could point me in right direction it would be appreciated. Thanks again.

Jenner

Cap the hard lines (or rubber vacuum lines) with a vacuum cap in the correct size and a zip tie around that.



A vacuum cap assortment kit can be found at Autozone, Pepboys etc

RSRRacer

Code is "P2004" which is related to cat efficiency. Any guidance on likely causes?



Could open exhaust be pulling fresh air to the back of Cat and rear 02 sensor? Is exhaust gas escaping too rapidly and not allowing enough heat at rear of cat?

Would a poor seal between the exhaust pipe and the rear of the cat cause this?

Thanks!

996FLT6

Someone mentioned on rl the header cat combo can crack ie possible leak? Mike

ScorpionT

It does happen from time to time. Cats also fail over time, but usually that is accompanied by the sound of pieces of the cat core in the muffler.