Cataltic Converter failure?, Catalytic Converter Options

[Justin73]

Hey all, I went to start my 95 Celica this morning and it runs like it's using 2 cylinders and is struggling to idle. I have a raspy sound from the catalytic converter when you accelerated, so I'm thinking that the Cat has given up the ghost. Can anyone confirm that this would likely be the problem? the Celica has only done 137000km but I'm going to get the Cat replaced tomorrow, so I'm hoping that will solve the issue, especially when it drove flawlessly the night before.

Cheers

J

[Box]

You can remove it from the car and inspect it before having it replaced and what not. A million things can cause bad idle. It's just odd that the cat would go out suddenly, usually it's a progressively worsening problem.

[Justin73]

True Box, I did notice a couple of days ago, when driving, the car slowed down a little then picked up again, maybe that was the warning sign. As for the Cat, it's a welded unit, not a bolt in, so it has to be cut out.

cheers

J

[Galcobar]

Odd that you'd have a welded-in cat, since as far as I knew the various versions of the Celica all used direct-fit, bolt-on catalytic converters. It'd also be quite odd for a cat to fail at only 137,000 km. You generally have to either melt the cat or plug it (both of which involve massive engine problems before the cat is affected), or else have exceptionally poor luck and get one with a manufacturing defect that allows the honeycomb to break apart.

That said, if the engine feels like it's missing, have you checked that it isn't? Problems with ignition, air or fuel are far more common that catalytic converter failures.

[Justin73]

checked leads,plugs and filters, all good, what has got me is that I parked the car overnight, started it up and to have this problem, especially when it was running just fine. I did have a sports muffler on, but had a baffled unit put on to lower the noise, maybe now, with a bit more back pressure, it might have caused it?

J

[Justin73]

Given that the Cat is a welded unit on the system, there is also a 'hot dog' muffler after that, it maybe an after market unit that was put on, but not in good condition, could explain why it didn't last as long as an original unit?
J

[JoshuaM]

First of all.... AUSSIE MEMBER!!! XD

Secondly, I second the views of a number of people above, aftermarket exhaust system or not, I would think it very unusual for the cat to be the cause of your troubles.

[Galcobar]

Slight changes in pressure in the exhaust system won't suddenly cause your engine to start stumbling. I'd be checking to see that all cylinders are firing, that the IACV is functioning, and the condition/colour of the plugs. I might also wonder about the fuel delivery, if it's inconsistent it can produce all sorts of odd problems.

[Box]

If the cat is welded in it's possible it's cheap Chinese garbage, which could explain the sudden failure. Check compression, check for spark, and then check to see that the injectors are working. If opening up the throttle some solves your idle issues I'd look into cleaning out the IACV.

[Justin73]

Thanks all, I intend to agree, a buggered Cat would not lead to barely starting and running like a lawn mower with fumes when first started, could someone link me the process for cleaning the IACV

cheers

J

Thanks Josh, yup another Aussie but like his American counterparts, we all have good taste in owning Celicas

[Justin73]

Well, just took off the air inlet to the TB, and found that it looks like it has never been cleaned. Looks like to me, a case of taking apart the TB and using carby cleaner and a tooth brush, fun times

J

[Galcobar]

Guide to removing -- and cleaning -- the 5SFE IACV. Your 3SGE should be almost identical.

http://www.toyotanation.com/forum/103-3rd-...s-pictures.html

[Justin73]

Thanks Galco I've taken out the unit and it was pretty filthy. I ve decided to replace the IACV, with a new unit, I hope this will fix the issue.

[Box]

Thanks Galco I've taken out the unit and it was pretty filthy. I ve decided to replace the IACV, with a new unit, I hope this will fix the issue.

More often that not a good cleaning and lubricating will bring back an IACV from the dead.

This post has been edited by Box: Aug 18, 2013 - 10:56 PM

[Justin73]

O.k, replaced with new unit, cleaned throttle body, still idles rough, and after a bit of smoke clears, it's still idling rough. When I go to start it, it seems to back fire/pressure then after second start, it goes into rough idling. It's got me stuffed as I haven't had much experience with EFI, it's almost like the distributor was moved and the timing is not quite right. Any suggestions all?
Oh, if it helps, I did a minor service, oil/filter and air filter, I also put in some injector cleaner (wynns) in the tank, maybe that has unsettled some fine matter in the tank and has blocked the EFI baskets?
Or, the only thing I can think of, would be the crank angle sensor.
J

This post has been edited by Justin73: Aug 21, 2013 - 5:09 PM

[Box]

I'd check the timing, it's worth a shot.

[Justin73]

I'll have a look Box, but would you or anyone on the forum know, where is the crank angle sensor located, or is it controlled by the distributor?