Catalytic Converter...

[funcat]

My Audi A4 started to misfire lately and it was diagnosed as a coil problem...the new coils are on order,but from reading infos about it I've found out,that this can cause a potential problem with the Catalytic Converter.Just thinking ahead I wonder when it will be a case of bad CC,can this be just replace with the "test" pipe? I know that this is easy to do,but it will affect the emissions...how strict are the check-in stations here? Does anybody have had an experience in this kind of the situation ?

[transam]

As far as l am aware only lead in fuel affects a cat.

[funcat]

As far as l am aware only lead in fuel affects a cat.

The not burn fuel going through the very hot CC can cause the damage...from what I've heard.

[transam]

As far as l am aware only lead in fuel affects a cat.

The not burn fuel going through the very hot CC can cause the damage...from what I've heard.

Hmmm, interesting, l must have a read. Thanks.

[sirchai]

Overheating

There are many problems that can cause a cat to overheat or fail. The most common cause is unburned fuel entering the cat. Also faulty spark plugs and leads will cause the engine to misfire and ruin the converter. The cat will also be ruined if the distributor timing is out.

Please see:http://www.cats-direct-shop.co.uk/technical-information.php

[Kwasaki]

Difficult situation for you, not familar with the A4 how many coils has it, and wouldn't think it would have a distributor or plug leads. ?

Not always possible for various reasons but if it was me I would not use the car if the backfire is regular, if the backfire is only now and again you may get lucky.

Cat's as I'm sure you know are expensive, hope the new coils solve the problem.

Removal of cats is possible but the ECU may have to be remaped as for the 7year check I think you refer to maybe a case of beer will solve any problems.

Edited March 10, 2012 by Kwasaki

[Woodsie888]

Here is a link to a site which explains cat's in simple terms including failure symptoms which may be helpful to the OP.

http://www.catalyticconverter.org/failure/index.htm

[MoonRiverOasis]

I actually got pulled for an on-the-spot emissions check just over 2 years ago.

Very scientific I must say - one BIB walked to the back of the car, then the other opens the driver's door and stomps on the gas. BIB at back visually inspects smoke coming out, and gives you a pass/fail.

I kid you not

The funniest part of it was, it was a brand new pickup on red plates (literally the day I bought it), that hadn't even travelled 100KM's yet, LOL.

To add a further twist to it all, the next day I was in at a tire shop getting upgraded tires fitted, when the worksop crew offered the "fix" the exhaust system for free, as part of a special promotion they had running. When asked exactly what it was they were offering to "fix", it turned out what they had in mind was to gut the catalytic converter with a piece of rebar...

Given my spot emmissions check the day before, I declined

[funcat]

Thanks guys...The package with ordered coils still hasn't arrived,so will have to wait till Monday.

The plan is to check what happens after installing new set of coils, then take off the CAT and see the insides...hope no damage...but if it is damaged,than will have to consider the "test" pipe...or the rebar

[Kwasaki]

Thanks guys...The package with ordered coils still hasn't arrived,so will have to wait till Monday.

The plan is to check what happens after installing new set of coils, then take off the CAT and see the insides...hope no damage...but if it is damaged,than will have to consider the "test" pipe...or the rebar

You won't be able to see inside without xray it's a sealed unit.

[funcat]

Thanks guys...The package with ordered coils still hasn't arrived,so will have to wait till Monday.

The plan is to check what happens after installing new set of coils, then take off the CAT and see the insides...hope no damage...but if it is damaged,than will have to consider the "test" pipe...or the rebar

You won't be able to see inside without xray it's a sealed unit.

I guess you can,if it looks like that

....otherwise one should see at least some light through...I hope mine is not gonna look like that one on the video

[Kwasaki]

Thanks guys...The package with ordered coils still hasn't arrived,so will have to wait till Monday.

The plan is to check what happens after installing new set of coils, then take off the CAT and see the insides...hope no damage...but if it is damaged,than will have to consider the "test" pipe...or the rebar

You won't be able to see inside without xray it's a sealed unit.

I guess you can,if it looks like that

....otherwise one should see at least some light through...I hope mine is not gonna look like that one on the video

Well if the backfire stops after new coils fitted and you have not got an unboltable type cat I would let it be.

The video set is good, it talked about unburnt fuel going into a cat so maybe there will not be any problem for you.

And the link " woodsie " put said look for heat-related discoloration of the converter shell.

It will be interesting to see how you get on, so goodluck and hope it goes OK for you.

Edited March 11, 2012 by Kwasaki

[funcat]

...and the story never ends...you can put me on the list of "thai bashers" now,but...the package finally arrived today and after I'd opened it I discover one of the coils connectors broken...how did this happened (?),simple...whoever packed that thing took it out from the original box(probably with the nice styrofoam bedding) and put it in some other (small)box together with two motor mounts,that I've also ordered...just like that,with a tiny bit of bubble plastic!...total lack of imagination !!

After the call to BKK,they said to sand it back...F#%@ ,if took one week to get it here,so I guess I will have to wait quite bit longer...it got in all the way from Germany to BKK OK,so it had to be packed right...no,they know better...idiots!!

[transam]

...and the story never ends...you can put me on the list of "thai bashers" now,but...the package finally arrived today and after I'd opened it I discover one of the coils connectors broken...how did this happened (?),simple...whoever packed that thing took it out from the original box(probably with the nice styrofoam bedding) and put it in some other (small)box together with two motor mounts,that I've also ordered...just like that,with a tiny bit of bubble plastic!...total lack of imagination !!

After the call to BKK,they said to sand it back...F#%@ ,if took one week to get it here,so I guess I will have to wait quite bit longer...it got in all the way from Germany to BKK OK,so it had to be packed right...no,they know better...idiots!!

I ordered a trick intake manifold from the USA for my Pontiac. Cast alloy. A nerd just put it in a cardboard box and yes, you guest it, a flange was bent and cracked. Perhaps the packer should have a degree eh.

[funcat]

Here is an update...the coil set came on Saturday...as I thought,they just changed the broken coil,not the whole set(!),but I don't think it makes any difference in performance,so "let it be"

...but before I've got the coils we did take the CAT out and inspected...it was not a "melt down",but it was pretty clogged since we could not see much "day light" though it,so...before i could suggest any alternatives,the rebar was already in it...after this "harakiri" the strait,perforated pipe was welded in and whole thing reinstalled.There was some(!) improvement in acceleration,so no complains so far.BTW,the guy says,that this is common practice here...they do it all the time,specially to Isuzu trucks...

After I've picked up the package on Saturday it was already to late to go to the mechanic,so I've changed the coils myself....Well,it's good to say-the car is "happy" again !!