Tell me about your stock exhaust (precat)...

[Cynic94rs]

I have a stock 94RS originally sold in CA, and as such it has a warm-up (or "pre") cat right after the exhaust manifold which connects to the downpipe.

I want to know which other years had the 4-cyl pre-cat, and if they came on Federal-spec MX-3's after 1994, etc.

Since I'm in CA, I'm thinking of trying to get away with fitting a CARB-approved 2.0 Probe Header on instead. As long as I have an EO # stamped on the header, what is the likelihood that smog technicians will notice the absence of the precat, or realize the EO # isn't for the MX-3 application, provided I pass the sniff test?

[Nomar]

I remember reading in a different post where someone said the pre-cat is only useful in filtering emissions during warmup. I had some toasted exhaust valves for a while and when i finally fixed them, my pre-cat had a hole melted in it so I just rodded it out and bolted it back on. I have a 96 RS up in Canada.

[torpedan]

From what i understand the informatoin they have is fairly comprehensive.

I am not very familiar with CARB but removing a CAT is essentailly illegal for street purposes. Given the level of stricness CARB is known for i am sure that that part has to be approved for use on that year range of car.

If there is real doubt on the issue call a local inspection station and ask.

[LongJohn]

I just had my 93 with the SOHC smogged. I was thankfully able to do this just before my BP swap. I had to go to a special "test only" facility where they scrutinize the car. I talked to the tech some.

Basically, if they find anything out of the ordinary, you have to go to an arbitrator (I think he said arbitrator) and explain the differences and somehow convince them to approve it. This sounds like a nasty problem.

My BP valve cover says "Ford" on top so I know I'll get nailed. I might buy a Protege valve cover sometime in the next 2 years if I still have the car.

I watched the tech, and he followed some of the wiring harness around, and looked around with a flashlight, so I know they are looking for things like the pre-cat, but I don't know if they look specifically for a pre-cat.