Iv'e got hot shot headers, random tech cat, 2.5" b-pipe with magnaflow resontor and a stock 2k2 muffler.

Some one that looked at my car today asked, i didnt even think about this before.

But i figured it would since it still has the main cat, and i have 02sims.

correct ?

headers remove precats....when the main cat is warmed up they dont do anything. make sure the car is warmed up and you will be fine

when i was explaining how a y-pipe works in eliminating the pre-cat to my dad's friend, he told me that my main cat would wear out quicker because the main cat now has a greater load without the pre-cat doing it's job... thats not true? pre-cats only do something when the car is cold?

the main cat has to warm up before it works. precats do the job until then.

lack of precats will not wear the main cat out

I just went to do my emisions and they did not check for anything comming out of the exhaust. all they did is pluged into my computer and checked for codes. thats it. so if you have no check engine light then you are good.

I have a y-pipe and resonator with muffler. No cat passed just fine. But with headers as long as you don't have "check engine light" then you'll pass.

not all states do the sensor in the tailpipe emissions test

Some states/inspection stations do a visual inspection as well, however I doubt 99.9% of them would recognize the lack of pre-cats.

ive had a y pipe on my 2000 max for about 50K miles and it never had a problem.

and im sure most people on this board that has had headers for years have never had a problem directly between the lack of precat affecting the main cat.

but ive heard running too rich could clog the main cat after extended use? which in that case it would be a tune issue if that problem does exist.

My 3.0 passed an emmisions test with Cattman headers and a highflow cat... The 3.5 should pass.

I'm in NYC...as long as your check engine light isn't on then you ok...your allowed to fail ONLY 2 of all the checks...Yesterday morning I had three so I had to drive around until I cleared one more...I had changed an O2 sensor thats why...but in the end i passed

Sux for us mang.

California ftl!


My setup:

Headers, straight b-pipe (not even a test pipe), turbo, axleback.

If anyone will fail, it's me. I got codes for EGR and stuff too haha.

My car just got checked for codes.No visual or tailpipe.

awsome, thanks for the comments bros!

You should be fine aslong as you give the car time to warm up fully. Take it for a good long drive before you go for emissions. I know in british columbia, for 98+ cars all they do is run the ecu for codes..too bad ill still fail even for that ( stupid jwt ecu p0136 and 3 for auto tranny)

Same thing here in Texas. No codes = pass