What is a back pressure suppose to feel like?

[Mighty Thor]

I'm not sure but I think my Fiero is experiencing some serious back pressure.

The cat. might be going. It did stall on me the other day and it now feels like it wants to stall everytime I drive it around. Every sensors, plugs, wires, emission stuff has been changed. I'm thinking this could be a back pressure because the exhaust does sound like it's choking.

I looked at its history and the previous owner did replace the Cat in 2006.

[dashboardrunner]

Re: What is a back pressure suppose to feel like?

what you describe sounds exactly like what my 01 silverado did when the cats went out... wouldnt hardly run at all!! sooo i changed out the cats and its like a whole new truck again...

[steddy]

Re: What is a back pressure suppose to feel like?

The way we used to do it in the dealer was we would put our hand over the tailpipe(s) while it was COLD and running and notice if there was any difference in the way it ran. If there was, we'd take it on the freeway and try to blow it out. If that didn't work, we'd replace the cat and that always fixed the problem. You can also tell by the sound. It just sounds like it's trying to move exhaust and there's a clog.

[Bonemaro]

Re: What is a back pressure suppose to feel like?

When my cat got clogged, it wouldn't tach past 2300RPM.

[StrtRacer98]

Re: What is a back pressure suppose to feel like?

When my cat got clogged, it wouldn't tach past 2300RPM.

x2, it will progressively get worse until the car no longer can run.

I replaced my cat's a few times due to them clogging, and it would start with the 'backpressure' your talking about, then your RPM's will just keep going down and you cant rev over a what the car cant exhaust.

You can cut a hole in the exhaust, pre cat and see if it makes it any better and that will tell you if the cat is cloggin up.

[pace2006]

Re: What is a back pressure suppose to feel like?

I noticed mine when the car had trouble accelerating with a moderate load. Had made a run to Sam's with a couple bags of dog food in the back and it was struggling on the uphill parts of the road. Didn't want to go over 40.

Finally convinced the mechanic that something wasn't right when I went for a little dry off run after washing it and it made a popping sound in the exhaust while shifting.

[Mighty Thor]

Re: What is a back pressure suppose to feel like?

OK, good feedback. I'm convince now it is the Cat.

I'll definately replace it and make this car purrrrrr again.

[StrtRacer98]

Re: What is a back pressure suppose to feel like?

I'll definately take it off and not replace it, and make this car purrrrrr again.

Fixed :D

[StrtRacer98]

Re: What is a back pressure suppose to feel like?

Err, forgot your in commiefornia..

Nix that

[bwkmaro]

Re: What is a back pressure suppose to feel like?

the best way to find out is do u still have low end power like crusing power but then u get on it and it has power for half a sec then u aint got nothing. another thing is mine went on my maro and it accually made it misfire cause it wouldent let the exhaust out the cylinders when the valves opened. just a couple of things to think about

[ATVrider89]

Re: What is a back pressure suppose to feel like?

I say it's time to gut that cat, as long as you don't have emissions testing where you live.

[Mad Max]

Re: What is a back pressure suppose to feel like?

I bought a few high flow cats on Ebay that worked really well for cheap $$. You may have to adapt them, it's easy if you have a lift and the right tools and pipe. Most of the stuff can be made up at a muff shop. I am installing headers on my 3.4 S 10 and had (2) 2 1/2 collectors made up at a local pipe shop. $10 baby. If you get a big enough cat, there is little to no restriction. There's a guy in Canada on Ebay that sells high flow cats for a reasonable price. You may have to get the ball socket for the rear of the cat, but that isn't a big deal. These cats look like mini torpedos, and fit nicely also. Only problem is the OBD 1 and 2 compliance cats for use in Californication. It's pretty strict there.

[Mighty Thor]

Re: What is a back pressure suppose to feel like?

I do have to smog the car this Dec. It barely passed last time.


I saw the one made by Magnaflow on ebay and it sells for 65 bucks for 49 states, but for Calif. it's 160 bucks. :omg:

Yes, we're very special here in Calif. :rolleyes: Pretty soon we'll be driving rainbow color cars. (they want to ban black cars :mad: )

[bwkmaro]

Re: What is a back pressure suppose to feel like?

that really sucks i dont how they think they can do that i live in newyork and emissions makes my life difficult but in cali it would really suck

[Mad Max]

Re: What is a back pressure suppose to feel like?

I guess when you drive into the SF Valley (Chatsworth) from Simi Valley and see the crazy colors in the sky from smog on a hot day... :tdown:. They take pollution pretty sreiously in Cali. I'm glad I was only there for a year and a half. Too bad, it's the land of cars. Anything that's high performance is there.