New exhaust - now car is running really rough

The cat may have been damaged while the exhaust was being changed, causing a partial blockage and mucking up the backpressure.

Guaranteed the cat has broken up and is blocking the exhaust system. Did your "mate" use a cold chisel and / or hammer (or air hammer) to remove the old exhaust. If so, hereinlies your problem.

Tim..

There's a leak in the system. A joint hasn't been done up properly or the system is not a good fit and has moved on its clamps.

Dave Baker - Puma Race Engines

I'm not at all sure why women like men. We're argumentative, childish, unsociable and extremely unappealing naked. I'm quite grateful they do though.

Ok, after talking to him it appears that he only replaced the back Silencer box and tail pipe, he said that the Cat isn't located in this area and couldn't have been damaged by his work.

Stu.

I've also noticed a slight smell of exhaust fumes inside the car wghich also wasn't there before.

Could one of the spark plugs have came loose?, is this possible? I had a closer listen to the engine and I seem to be able to hear a blowing/sucking sound coming from one of the spark plug sockets, could this be the gas escaping out the plugs?

My mate has the necessary extension socket thingy so I'll try tightening those up in the morning.

"stu" mumbled:

Oh yes it could. Rough handling can cause enough vibration to damage the matrix even from the other end.

Lol, ok - I put the socket over the plug and started unscrewing with no force at all, it was just spinning in the socket, the plug appears to have broken up inside the engine whilst running!

The screw-in part of the plug is now stuck in the engine and the rest of it is sitting here on my desk!!

lol

Stu.

Oh dear.

You need a experienced mechanic now!

Going back to your original problem it sounds like the failed plug was the cause of the rough running and lack of power and hissing noise. You didnt mention this mis-fire tho! We assumed the exhaust work had broken the cat and blocked the exhaust...

If you disconnect the fuel injector plug on the affected cylinder it will be safe to drive the car on 3 pots a reasonable distance without damaging the cat from unburnt fuel.

Usually its possible to drill out any remains of the electrode of the plug and then use a suitable stud extractor to wind out the threaded part thats still in the cylinder head. If not, then the head will have to come off and possibly fit a helicoil insert in the worst case scanario.

Tim..

Its 'getoutyerwallet' time!

I thought I might. :-)

mention this mis-fire tho! We assumed the exhaust work had broken the cat

Sorry I didn't give full details initially.

How do I find the injector plug?

I tried starting the engine....it started ok, very rough though....then there was an almight pop / bang and the remaining ceramic part came rocketing out the socket (so no drilling needed, lol) I'm borrowing a stud extractor tomorrow, so hopefully all will be well.

Any idea what would cause the plug to disintegrate inside the engine? I've never had this problem before.

Thanks for your help. :-)

Stu.

That may have been interesting to see :-)

4th car, probably 150-200k miles driven in 11 years of (mostly) home servicing. Only had one spark plug snap, and that was entirely my fault handling it roughly. Never happened spontaneously.

Cynical mode? Return business for original garage? "Seem to have a problem there Sir. Just leave your credit cards & we'll make it right as rain".

Pete.

Some good advice from u there mate , thanks :-)

I've disabled the fuel injectors as u have described, but when i start the engine their is a loud putt-putt-putt coming from it, i suppose this is the gas escaping from the cylinder up through the empty sparkplug hole?

Is there any way that running on 3 cylinders will damage the engine?

Thanks again,

Stu.

them up to

Don't want

unscrewing with no

appears to have

the rest of it

A stud extractor _may_ remove it, using the hole now in the broken piece. Don't try drilling it. Unless you reverse grind the drill bit and run it backwards. Running forwards could result in the broken piece being screwed into the combustion chamber. The head would then need to be removed to get it out.

Personally I would try using the tang of a file, or even a screwdriver with sharp corners. Tap the end to key it into the hole, then try unscrewing it. Mike.

After 2 broken screwdrivers I finally managed to get the bugger out.

1st screwdriver somehow jammed in the plug and the handle came off as i was trying to remove it, I used a 2nd screwdriver and jammed that down into the tiny space left, then started turning it with a pair of mole grips, after a thousand tries it finally started moving. :-)

Engines now running sweetly.

Thanks for all your help guys!

Stu.