Bad cats?

Hock

Registered User
Ok, pretty sure the cats are bad on my SC, but let me know what you think.

The car is pretty much stock, except it has a CMRE Stage 1 cam, Port matched heads and intake, ported manifolds, and homemade CAI (more like hot air intake), BBK FPR, Double Roller Chain. It has stock exhaust as well and stock S/C pulleys.

Now the car has been a little doggy since I did the parts swap. I also did a 5spd conversion and still have the auto EEC. I have been blaming the EEC for the doggyness of the car but now I have second guessed myself.

This past week I got some new shifter parts on the car and took it for a drive. I took a friend of mine with me to so he could see how it runs since I replaced the bad FPR. Well I burried the throttle and then the boost gauge. If I had to guess how high it went I would have to say around 16-17lbs before I could even hit the redline.

NOW, when I bought the car it had blown head gaskets. When I pulled the DS head some coolant found its way down into the cat. That all got burnt out when I got it running.

I'm thinking, between that and a bad FPR that I very well might have destroyed the converters and they are now causing a blockage in the exhaust resulting in way higher than normal boost pressures. BTW, I was only seeing 10lbs when I parked the car 5 months ago because of the trans losing reverse.

Let me know what you think.
 
call a exhaust shop and see if there is a way to measure exhaust flow. i seem to remember my local exhaust shop having a tool they stick into the exhaust pipe to measure flow to help determine the condition of the cats.
 
Considering the age of the car etc, I would suggest replacing them and replace that stock resonator while your at it. The stock exhaust from the resonator back to the bumper is fine at your mod level.

As for the computer, there is very little difference between the auto and 5spd ones except in the area of dashpot functions etc.

Fraser
 
Considering the age of the car etc, I would suggest replacing them and replace that stock resonator while your at it. The stock exhaust from the resonator back to the bumper is fine at your mod level.

Fraser

I have a full exhaust sitting for it, the problem is I had on my last SC and it had headers. The headers did not get carried over to my 92 so I have to take the complete system to a exhaust shop to get it fitted to the ported stock manifolds.
 
The dashpot functions control how "soft" the landing is to idle RPM from high RPM. Some folks that have done the swap have reported either a hanging idle when shifting, or the car stalling out.

Oh, and idle RPM is a bit different. The 3 main things that would affect power such as air, fuel and spark, are literally identical.

Fraser
 
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