I have a 2006 monte carlo ss and i want to know if i put a high flow race cat on my car will i throw a check engine light and if so is there any way around throwing a check engine light. any help would be appreciated.

 

Yes, it is possible. The 3800 people used to be hit or miss with 'high flow cats'- so unless you buy an OEM replacement cat, there is no guarantee that it won't throw a code.

Really though- why waste your time? Its a lot of money for no real performance gain. Even deleting it completely won't yield much performance gain.

The way around the code is to find someone with HPTuners- they can set the code so it doesn't report.

 

thanks appreciate the info

 

i thought that alot of the ls4 cars were seeing gains from the hogan catless downpipe, but i do agree if your going to do it then you should go catless. some guys were saying going catless with a tune they picked up a few tenths.

 

Have you seen anybody do an A-B dyno of just a cat delete? I'm curious to see the actual whp results, and I don't get on LS1tech super often anymore.

Also, with getting the DP too- you'd have some gain from the higher flowing downpipe alone.

My point here is, modern cats aren't as terrible for flow as many people think given their history; and the gains from a high flow cat or even a complete cat delete is not going to be some massive whp gain like with the early design of converters. Plus, then you have an illegally modded car as well- I'm sure if exhaust shops get a big fine for removing a cat that- that you could also get a ticket for it if someone happened to look.

Sure, but a good tune could've made most of the difference there also.

 

i agree the new cats arent like the cats from back in the day.i havent seen any back to back catless vs catted, but there are multiple cars on tech that had the catted hogan downpipe with the car tuned and swapped to the catless and picked up tenths. i see that as an improvement. all honesty if i was going to do a highflow cat i would just get the catless downpipe it bolts in and theyre both going to set off the check engine light.