jkstill

iTrader: (11)

Can someone recommend a good muffler shop in the Beaverton/Hillsboro area?

A shop you have good experience with?

I suspected my FC exhaust is somewhat clogged.

Between 1500/2500 RPM the car can run pretty rough at times.

The usual suspects have been eliminated - vacuum hoses replaced, all intake gaskets, injectors cleaned and flow tested.

So, I took it for a drive without the oxygen sensor to relieve any backpressure. (A noisy and smelly drive)

It seemed to run better w/out the 02 sensor, so I need to get the cats checked/replaced.

BTW, anyone here have experience passing Oregon emissions with the precat deleted?

I imagine that like the FD, once the car is warm, the precat doesn't matter.

I really don't want to pay for 2 cats.

jinxed4dub

iTrader: (7)

I don't know a muffler shop, but no muffler shop will disable or bypass your precat. Its against fed law, so they cant do it. I'm sure you can find a relyable person to do the work though. I had aftermarket header in my lancer. witch eliminated 1 cat thats in the exaust manifold it self. I passed deq. so you should be fine. theres also a mix in to your gas pass deq additive. I'm not sure on price or what its called. Ive seen it at multiple part stores. I cant say on how it works or if it does. I didn't use it.

a friend of mine in a 626 wouldn't pass deq because of a cloged cat we removed them. and hollowed them out. He passed without additives also. this is what I'd recomend. you'll have to buy 2 gaskets. and do it yourself. or have a shade tree mechanic (that guy with cars in his yard) do it.

jkstill

iTrader: (11)

Hmmm. I hadn't thought of that.

The car needs to be able to pass emissions. Guess I could get a RB head and install that, and then just replace the main cat.

jinxed4dub

iTrader: (7)

before you spend all that money, try to hollow them out. if your cars running right you should be able to still pass the smell test. it will also tell you if thats even your problem. you don't want to blow a bunch of cash and get nothing in return but what you already had. you do get a little proformance from this also and it wont cost you anything but some gaskets.

to hollow out the cats just use a long stick (like a wooden mop handle) and ramrod it through. it just breaks out. theres some platnum in those ******* also try and salvage that for some more cash.

Derekcat

iTrader: (8)

>_< How could it possibly pass with a gutted cat?

btw, yes Exhaust shops [ASE Certified] will remove your precats, because the newer cats are better and can do the job with just one [they apparently have started using another chemical or metal in the cats that makes it better..]

To pass DEQ: two bottles of Isoheet into 1/4~1/8th tank of gas, airpump output to cat extension pipe [the one that goes from the main cat to the engine bay] and you WILL pass.

But you MUST drive VERY lightly to and from DEQ, fill up the gas immediately afterwards, and DISCONNECT the airpump from the cat extension tube..
[This is how I've passed ever since I got my clogged cats replaced by a single good cat]

jkstill

iTrader: (11)

I find that a muffler shop is not needed, a couple of different bolt on options are available from rx7.com:

http://rx7.com/store/rx7/fcexhaust.html

jinxed4dub

iTrader: (7)

I've past a car Mitubish lancer with no precat due to aftermarket header, and a gutted stock cat I still had the airpump hooked up but the 02 sensor was disabled with a 15 dollar part that I got from road race motor sports. and thats how my old nieghbors 626 past. He went in they said his cat was clogged. we hollowed it out and reinstalled. it passed with no fuel additives. but if your worryed get the additive. I'm willing to try deq with out my rats nest and no airpump. they don't really look I could just mount the pipe that goes to the air pump to make it look lagit. If your cars running good it should pass. also don't drive it slow spend a day driving it like you stole it and work out any excess carbon. that should help you pass. just make sure your all tuned up. new plugs and wires should help produce a stronger spark and burn of more fuel so no gas is coming through causing you to fail just on the smell. I have no cats, and my airpump isn't going to my exaust, and it doesn't smell any differnt than when i got the car.

I beleave its against fed law for them to remove any of the cats. if the car came with 2 it must have 2, if it had 3 it must have 3. most cars came with 1. idk why we have more, but my lancer did also. gutted cats pass no issue. if however your emitions is messed up other places you will fail. also if your check engine lights on auto fail.