Ca smog woes

[supraman7mgte]

I have a 91 Sup that I plan on getting on the road again
Its been parked since 2014 when gas prices were ridiculous
Last time I smogged it it passed by the skin of its teeth
I attribute that to the fact that it had some bad valve stem seals and might have contaminated the primary cat and I think that's why the hp is suffering.
My questions are,how many cats did this car come with and how many does it need to pass smog?
Is the BIC downpipe legal in Ca for on road usage?
Could the valve stem seal issue have caused my problems?
Thanks for any reply:icon_bigg

 

[plaaya69]

The non turbo Supra has 1 cat (about where the transmission is located) and the turbo Supra has two (one on the down pipe and the other is in the same spot as the non turbo). I would say your BIC downpipe probably has no cats built-in so it probably will not pass emissions unless your 2nd cat is very efficient. I bet you can find a OEM downpipe and just swap it out for you smog and I have also heard of people cleaning out their cats with different types of cleaners but you may have to research what to use. Also yes burning oil and other fluids through the exhaust can ruin or mostly clog your cat.

 

[Asterix]

We need more information about exactly why your car didn't pass. Was it because of CO, NOx, or HC? There's a different mechanism for each failure.

If you're talking about downpipes, you probably want to post in the Turbo area, rather than the NA area. The NA has no downpipe.