Mtl20v

I just installed a custom exhaust on my friends s500 and he gets a cE light. wheni plug in the OBD2 reader, i get the code "CAtalyst threshold exceeded bank1" and the same code..but bank 2.

2 minutes later the ESP malfunction and ABS lights come on.

Anyone have any ideas to why this happened?

elchinocache

did you leave in all of the original factory o2 sensors. another thing could be that the computer doesnt comprehend where the back pressure went so it goes haywire and throws error codes that may neccesarily be accurate. Also the ce light only comes on when something with the engine emissions or intake system has gone astray.

Mtl20v

Yeah..the o2 sensors were not changed. It's a catback exhaust system. and The O2 sensors are right before and right after the cat. It's quite odd.

Today all of a sudden the Air system light came on and the rear is lowered.

fkong777

wonder if the installation heated up some wire/ hose/ sensors. causing it to fail.

Custom Catback That is a lot of pipes to weld.