Not sure how long you had the car and what you mean by a little rough. When I put the factory recommend champion copper plugs in (for chrysler motor) and removed the iridium plugs from the previous owner I noticed a big difference

Plugs, wires, fuel filter, cold air intake, general maintenance really. Dose the car have any codes?

It's running a restricted exhaust code I believe it's my can and when I say it runs rough I mean it has no power off the launch

Sorry ment to say car

Cat * freakin auto correct

Then you should get a new cat. A plugged cat can make a car run like crap.

You can also hollow out your cat or delete it all together but you will loose some back pressure.

Man these imports are hard to mess with compared to the big v8 I'm use to . What about a test pipe instead of cat

You can do that but like I said you will loose some back pressure and will probably throw a code. The rear o2 may pick up that the cat isnt there anymore.

How much should a new cat cost me or should I just buy a new exhaust headers down pipe the nine yards

Its all in what you want to do. I think the auto parts stores sell universals for under 100 bucks but would need welded in. I would personally just get an aftermarket exhaust and put a high flow cat on it or somthing. If your going to be messing with the exhaust allready why not go the whole 9 yards.

Agreed I've gotten megan racing headers and down pipe then after the cat I'll put an hks on it

I get no codes running a test pipe buy if you need to pass emissions you might want a cat.

Op has a 98. 96 and newer get the new test so as long as he has no cels he should be good.

Ok thanks guys for all the help

Go all the way with it ### if u half step you might come up with another prob

colton2g said:

It's running a restricted exhaust code I believe it's my can and when I say it runs rough I mean it has no power off the launch

Sorry ment to say car

Cat * freakin auto correct

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what code do you have exactly??

I'd have to hook up my scanner and I'm out of state for a few weeks sorry had a business trip

colton2g said:

I'd have to hook up my scanner and I'm out of state for a few weeks sorry had a business trip

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thats alright.

another helpful tid bit is the MAP sensor can cause rough engine operation and also lack of power when it goes bad, i would look into that a bit. and also make sure your TPS sensor is working, without the proper demand input to the ECU the engine can experience rough conditions and loss of power at times. and i do agree with everyone else on the restricted catalytic converter as well that can cause rough idle and lack of power at idle and engine revs.

Well it idles at right under a thousand and when I'm sitting still it will drop try to die and then kick right back on and run fine. I've also found out that if I'm sitting at a light and it acts like it's gunna do it I pop it into neutral and it's revs come back up by the way it's and automatic

colton2g said:

Well it idles at right under a thousand and when I'm sitting still it will drop try to die and then kick right back on and run fine. I've also found out that if I'm sitting at a light and it acts like it's gunna do it I pop it into neutral and it's revs come back up by the way it's and automatic

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are you saying sitting still as in park or in neutral gear position??

Like sitting at a light or something I've move it from drive to neutral the revs go back up

colton2g said:

Like sitting at a light or something I've move it from drive to neutral the revs go back up

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the reason the revs go back up is because your taking the load of the transmission off of the engine and that allows the revs to come back up.

a way to check if the exhaust is restricted is to hook up a vacuum gauge and put the car in gear and power brake the engine ( one foot holding the brake to prevent the car from moving and the other foot holding the engine at 2k rpm) and watch the vacuum gauge. if the vacuum drops from 14 inches of vacuum to near zero then the exhaust is restricted.

id also suggest to smoke the intake to make sure you don't have any vacuum leaks.

without the exact code its difficult to know what to do. CEL give you a direction to go on for troubleshooting, with out it your basically checking all of your basics like fuel pressure spark vacuum and such (just examples).

Ok I'll check it out

colton2g said:

Ok I'll check it out

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good luck to you