yendor
Well-Known Member
Re: I Want To Remove My Cats. Can?
Manufacturers install pre and post catalyst sensors to check the quality of the exhaust gases. The one before the CAT ensures that exhaust is in a reasonable range for the CAT to handle and is usually used to change AF ratios. The one after the CAT is used to monitor the final output of exhaust. Anything above a preset level and it tells the car that the CAT is kaput.
So when you remove the CAT, both pre and post sensors see the same amount of NO2 and CO levels and hence your car raises an alarm cos it thinks your CAT went kaput. There is a way to prevent that but it's a trade secret. Ask your friendly neighbourhood exhaust shop to solve this problem.
As for the M54 engines (which i love...ha hah..) The pre CATs are there to clean up the exhaust a little and to heat it up further before the main CATs do their thing. The only reason i can think of is because, here in asia, we do more city driving and at lower revs, the CATs dun heat up enough to be effective. Hence the need for the pre-CATs to get the enhaust up to temp.
Cheers
Manufacturers install pre and post catalyst sensors to check the quality of the exhaust gases. The one before the CAT ensures that exhaust is in a reasonable range for the CAT to handle and is usually used to change AF ratios. The one after the CAT is used to monitor the final output of exhaust. Anything above a preset level and it tells the car that the CAT is kaput.
So when you remove the CAT, both pre and post sensors see the same amount of NO2 and CO levels and hence your car raises an alarm cos it thinks your CAT went kaput. There is a way to prevent that but it's a trade secret. Ask your friendly neighbourhood exhaust shop to solve this problem.
As for the M54 engines (which i love...ha hah..) The pre CATs are there to clean up the exhaust a little and to heat it up further before the main CATs do their thing. The only reason i can think of is because, here in asia, we do more city driving and at lower revs, the CATs dun heat up enough to be effective. Hence the need for the pre-CATs to get the enhaust up to temp.
Cheers