I have a 98 prelude that has an aftermarket eastern high-flow catalytic converter bolt on. The bottom of the end of the header and everything after that is busted up and scratched from my flying up and down cement hills. There is a heat shield looking pipe that goes down from the header and leads to my high flow cat, and it is leaking something. Could this have triggered my check engine light? I had the cat installed after the cel code 67 went off 2 months ago and all was fine until it went off again. what could be wrong

 

you could of messed up the sensor that is on the down pipe.

 

What year is your car? OBDI or OBDII?

 

think he said its a 98....so i would assume if he would have obdII less he swaped

 

its a 98 prelude (non SH)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dre2day &raquo;</TD></TR><TR><TD CLASS="quote">think he said its a 98....so i would assume if he would have obdII less he swaped</TD></TR></TABLE>

That he did. I am usually good at reading the whole post too. LOL

Anyway, I think the leaking downpipe would very well be causing your CEL because OBDII cars have an O2 sensor in the cat as well as the header downpipe.

Is there any way you can patch the hole in the downpipe temporarily test to see if it's causing the issue?

 

Yeah, use some cement exhaust repair where its leaking to see if that clears code up.

To find leak use long narrow tube while car is running. Put tube to your ear and move the other end around your exhaust. It would help if someones pushing on the gas here and there to make the sound louder (hotter and colder game)

Or option two is to spray a warm non comustible liquid in various places and see if it bubbles. If your exhaust is hot DO NOT spray a cold liquid on it or it could crack.