The car idles ok, but when you put it in gear the car is slow as hell and has no power. It just started happening recently and the other day the CE light came on. I had codes pulled and it had something to do w/ emissions and the guy suggested the cat may be going out. The car has 2 new coils,4 new plugs, coil cover, cam sensor, intake air temp sensor. I am going to pull out the plugs and see what they look like but its not misfiring or bucking like an ignition problem. The trans still shifts through all gears and you can drive it but damn its slow. Seriously a geo metro would take me in the 1/4 mile. Its pretty bad when you can't even pull out into traffic until the road is clear. This car will downshift out of OD if you get on it like 3/4 and the rpms stay at about 4 but it can not pull except very slowly.

Now I'm thinking the cat may be plugged. I don't have the $241 to blow on a bolt in replacement from the manifold to the rear exhaust section w/ the flange. I was thinking about removing the cat altogether and getting a CE light eliminator plug to fool the rear 02. Anyways I know its illegal and all that but in Michigan where the car is registered there is no inspections or emissions. I am going to be repainting it and selling it soon but I have to get it to run good again. I need to know the diameter of the pipe so I can get the right "off-road" test pipe to put in place of the cat. Plus with 118k miles I'm sure the car will run better if the exhaust can breathe. May also remove the resonator directly after the flange. The car still has the stock muffler which I want to replace with a high flow but I don't like the "tuner or ricer" mufflers that make these cars sound like @!#$ty weed whackers.

Anyways has anyone had a problem like mine that they found out to be a clogged cat. I can't think of anything else it could be. We had a transmission put in it last summer and it works fine, goes through all the gears. So if its not the transmission, and its not the ignition, it must be getting choked off and the only thing that comes to mind is the old stock catalytic convertor. Sound logical? At idle it would run smooth since it doesn't need to flow much air, but when you are getting on it and it can't breathe you get no performance. Like trying to run a marathon race breathing through a straw.

Any suggestions?

Something has to cause the cat to go bad. You could have ran it too rich at one point or had a missfire. Could get a clogged fuel filter.


My cardomain

whats specific codes were pulled.....if you suspect a clogged catr the remove the back half of the exhaust system and run it open head and see if there is a change in performance

It said catalyst below threshold or something. They looked in the book and it suggested replacing the cat. I thought they were nuts.

Ok, I drove it around last night some more. Ran the transmission through the gears manaully. No matter what gear its in, it pulls slow as @!#$ and it won't rev any higher than 4000 rpms. If you hold it in 1st and stand on it, it hits 4000 and just misses, so I let off don't want to blow it up.

Could the ignition control module be fried? I'm surprised there is no code stored right now for this. I mean you'd think the car would know its running like ass. It feels like it has the power of a 2-cyl but it doesn't miss or buck till 4000 rpm and it will not pull any higher.

I'm getting ticked. I don't think the cat would cause this.

I pretty much had the same issues as you.. My troubles were they same but my car wouldnt shift unless i let off the gas, so much pressure! you can get a high flow cat for like 60 bucks man.. if you dont want to pay for a new cat hollow it out.. but dont run the car without one.. for simple fact sometimes cops look under your car (speaking from experience) and a no cat fine/ jail time isnt fun trust me..




beer is like a chick.. well not really its just beer, it be cool thou huh?

Jen Bierman wrote:It said catalyst below threshold or something. They looked in the book and it suggested replacing the cat. I thought they were nuts.

Ok, I drove it around last night some more. Ran the transmission through the gears manaully. No matter what gear its in, it pulls slow as @!#$ and it won't rev any higher than 4000 rpms. If you hold it in 1st and stand on it, it hits 4000 and just misses, so I let off don't want to blow it up.

Could the ignition control module be fried? I'm surprised there is no code stored right now for this. I mean you'd think the car would know its running like ass. It feels like it has the power of a 2-cyl but it doesn't miss or buck till 4000 rpm and it will not pull any higher.

I'm getting ticked. I don't think the cat would cause this.

Code P0420- Catalyst Efficiency Below Threshold (Bank 1)

Basically, means either your cat is dead or your O2 sensor is dead. Since you can't get it over 4k rpm, I can guarantee that your cat is clogged. I had this same problem. Order yourself a cat from here. Get part number 94035. This is a high flow cat with a 2.25 inch inlet and outlet, and the o2 bung is built into it. If you have a different size pipe, then get whatever cat you need for it, but if you have a full exhaust setup, I'd hope that you are using 2.25 inch. Anyway, get the cat replaced and your car will be good as new!


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injectors? would suck but a possibility?

The cat was plugged almost completely. I bought a new one for like $53.00 it was a universal light weight one. I'm not sure about high flow but its a lot lighter and smaller than the factory one. I had a shop cut off the old one and weld on the new one.

My boyfriend got under the car the other night and after it sat for about an hour, the exhaust manifold was cold and the rest of the pipes were cold but the cat burned his arm it was still so hot. We knew then it was probably plugged.

Thanks for all the help

Now I just gotta get the windows tinted, and the car painted, and then its for sale.