Thread: Choosing a non-metallic, OE-quality cat for a 3" downpipe?

what year is your car? what cat you need will be decided by your year.

i got a ebay 3 inch hi flow cat for 50 shipped. needed it to pass inspection here in NJ. but i also have a tuner so i killed the codes.

with a 01 you need a oem type cat, and even then, you may get a cat code.

there's a good chance any high flow cat will throw a code. it's doing its job , it's just the sensor thats not convinced.

I may not be up on my year to year changes, but I run an emulator alongside my hi-flow cat (2.5") on a '99 and have no issues. Is that an option for you?

he needs the cat test shut off in tiny tuner. then he can run what ever he wants to. 01 up cars are messed up when it comes to changing the cat. the cat test just dumps fuel and thats no good.

if its to be used with dhp your all set.

You know what's really odd Scotty? With my 04' PCM it doesn't do the cat test the same as the 05' did. You would notice that the vacuum level would change when sitting at an idle every once in a while. I have not seen this in the in the 04'. The other thing I notice is that the base timing in the 04' is 18* but in the 05* the base timing was 5-6*.

Jeff

wot on a 05 is 18 degrees timing.

i dont think you can feel or even know the cat test is happening. evap may make vac change.

No I mean at idle it is 18* on the 04' PCM the 05' was 5-6* at idle. I couldn't even feel it either just see the boost gauge go from 19 to 10" then back. May have been the evap, but I did notice the 02 would go rich or lean, can't remember now at that time then start switching again that's why I was thinking it was the rear O2 test

iirc when i was running 05 timing it was around 19-21 at idle. it was like 42 cruising on the highway too.

I do see 38-42 or so on the freeway with both years. I need to put the 05' back in there and try it again since my problems been fixed for a while now. Then try again. Lol

Jeff

I was going to say, I highly doubt the timing is set that low at idle.