Printable View
I'm no mechanic or anything. But I know that removing the cat will remove a significant restriction in your exhaust system. If it seems to run better/faster with the cat removed, it doesn't necessarily mean the cat is bad, just that the exhaust is less restricted now and therefore less resistance for the engine to contend with, and possibly that is compensating for a problem that is still there.
-Tim
So the timing checked out okay?
haven't checked the timing yet, going to pick up a used cat from Gary tomorrow morning.
we'll see what happens.
Why, ya just posted that with no cat it still runs like crap? I'm confused on how a used cat going to make it any better?Quote:
Originally Posted by Billy Blaze
Opps nevermind I saw where you edited your cat test post. ;)
ok my next what would you do question.
I could buy a used cat that may or may not work or buy a new one.
I would like to have the new one but can't afford to spend the $ if it's more than the cat, since i will have to have cash for the timing issue, if there is one.
Is there a way to test a cat, so that I could test my old cat....short of installing it on another car and seeing if it works?
A simple test is to shake it. But that isnt 100% conclusive. If you hear stuff rattling around there is a good chance the cat has broken up and could be clogging the exhaust. You might try a muffler shop too. I bought a new after market cat online and took it to Marc's mufflers in benbrook. I added the cat to my racing beat mid pipe which didnt have a cat. You could even do that if you wanted, buy a racing beat mid pipe to use for a while then when you get a chance add a cat to it and be legal.
I don't know what the exact symptoms are, but unless it's smoking or puking oil, I'd guess jumped timing belt - and the symptom of that would be a wildly loping idle, rough running, and/or not running at all. Sounds like you're easter-egging it a bit here - not that I blame you, but jeez. My money would be on you finding/fixing the problem with the car you've got - I don't think you'd get shit for yours as-is (and parting it out would not get your money back - although I'd love a crack your MP62/intercooler :rolleyes:).
Keep us posted...!
hey Majik, i did shake it to see if anything would rattle around inside, there was some rattle but not a lot.
I turned it so that the daylight yesterday would shine into the pipe and the screen was completely clear of any obstruction.
when the original tuning was done there was a time when the car would bunnyhop and jump, popped random misfire codes, bog down etc.
This could have caused the cat to fail or maybe it just failed at 66K.
I dont know how long they last.
And I'm not trying to point fingers.
I also thought that the cat may have been going out all along even though I noticed no symptoms, and that is why the tuning couldn't be nailed down and it failed under boost. If that is the case the problem may be solved by simply putting on a new cat and re-tuning the car ( I would think).
I'm going to get a used cat this morning to see if there is improvement.
If there is and it doesn't completely fix it I will pull the valve cover and do the timing test.
If it has jumped time, will i need to tear it down as I would with a timing belt change...take the belt off turn things where they line up and put the belt back on? that seems logical to me but i didn't do the service on it so don't know.
trickyrix if you would like to make an offer on the SC/IC PM me, as I will more than likely be pulling it once this is fixed. I would be throwing in the oil catch can, K&N intake and 350cc injectors, powercard and injector harness.
Hmmm....
Have you ever got any codes related to the timing sensors? Also, have you gone through the wiring harness at the front of the motor where the lower sensor is on the crank?
Since this thread is titled, "If it were you, what would you do?" I'll tell you what I would do.
I'd check the timing, as described earlier, and much easier IMHO than messing around with the cat. You said it was still sluggish with the cat off, right? It's highly unlikely the cat just died all by itself at 66K, unless caused by another issue that needs to be identified first.
That is what I was thinking as well. There has to be a reason for the CAT to fail, and if you don't address that first, you are just going to end up with a second fouled up CAT.Quote:
Originally Posted by cam76034
If I was you, I would quit screwing with it and let someone that knows what they are doing fix it! Every time you touch it, something else goes wrong. Not everyone has the aptitude to fix these things. Leave your ego at home and take it to Rogue.
From what I understand if you can see thru the cat then its ok. More or less. Cats fail by melting the innerds and or break down into small pieces hence the "shake test" .Quote:
Originally Posted by Billy Blaze
I'd pull off the cam cover and see if the cams are still properly aligned. It will only take a 10mm socket, a 10 or 12mm box end and 10-15 minutes total.
I to recently had a similar problem with my cat after dumping to much fuel into the system. The cat made the car slow spool slow idle poorly and generally just ran like Arse. I did replace the cat with a brand new $100 cat at a local muffler shop (Same one that FM sells for way more than that) Only thing is that I drove it so long like that I think it contributed to my downpipe breaking in half. But since replacing that part as well the car idles better and has a noticable extra 50 HP (Previous Dyno showed 202 RWHP at 15PSI and now its showing 215 at 5 PSI
No codes like that so far, i have had random misfire and system too lean.Quote:
Originally Posted by channelmaniac
I haven't checked the wiring harness either...would this be something that could be cut or come unplugged etc?
I haven't done anything to the car, except pull the cat off.Quote:
Originally Posted by MadMerv
and these problems arent a result of me doing anything wrong.
This is what i was wondering as with before the 350cc injectors, it was dumping too much fuel and causing the random misfire.Quote:
Originally Posted by MiataMike
Since the 320cc injectors were installed I have had the lean code. but the car ran better.
I am wondering if the backfiring etc from the initial problem caused or contributed to the cat.
I should have more info in an hour or so when I get the new/old cat on.
If it's not the cat I will get a refund so that's cool just out 60.00 in gas.
And if the cat doesnt fix it I will pull the valve cover and look at the timing.
The reason I ask was the harness could've been damaged because of the front end collision your car was in... I would think that it would've given you a sensor code if that was it though.Quote:
Originally Posted by Billy Blaze
RJ
I give up :(Quote:
Originally Posted by Billy Blaze
Billy...I'm no expert....I have replaced the cat on mine more than once and I won't discuss why here....:rolleyes:. I can say three things about your problem.
1. It's not the Cat
2. It's not the Cat
3. It's not the Cat
Check those timing marks.....
Good Luck....
Jerry:D