headers

[USCS14DUDE]

I have a 95 240 with hotshot headers installed on it. My check engine light came on like it should have since the first cat was completely gone. I had an exhaust shop move the second o2 sensor to behind the second cat, but the check engine light is still on. Now i'm sure this is a common problem and what have people done to get rid of it?

[daniel240]

the 2nd 02 sensor is already behind the cat, it is behind the 2nd cat. unless im just not understanding you. my CEL never came on when i installed my hs header.

[USCS14DUDE]

hmm....thats strange because my second o2 sensor was between the first and the second before i had it moved. what year is yours? is yours OBDII? maybe thats the difference between ours..i dunno.

[Camel]

CEL will usually come on if you install the header without relocating it behind the replacement cat you have to install in the second cat's location. this is because you replace the primary cat with the header and the two sensor readings are not within tolerances anymore with no cat between them.

[daniel240]

mines OBDII thats probably what it is.