Exhaust blockage?

[chrisash86]

Driving home tonight when at low revs it hesitates to accelerates and makes a chugging noise in the exhaust then it clear and return to normal ? Possible exhaust blockage ? It's a new exhaust well a few months old and it a 2.0 16v engine red top gsi!

[Mk3alan]

I had a similar thing with my Astra, performance was awful just wouldn't go.
Took the back box off but it didn't make any difference, took off the centre box and found the what looked like wire wool had come out of the silencer and was rammed down the exit pipe.
I couldn't believe how solid it was and that the engine ran at all!

Alan

[humbucker]

Failed cat?

[chrisash86]

Cheers Alan, humbucker it's a new full system so I hope it's not that lol

[Cavalier342]

Is it not a mis-fire? Could be a loose HT lead, if you say the exhaust system is new, then it may not be blocked.

[colin1]

Cheers Alan, humbucker it's a new full system so I hope it's not that lol

If you put the palm of your hand to the exhaust, how much back pressure do you feel you're getting?
If someone revs it while you do this, is the change commensurate with the change in revs, is there a lag between applied revs and change in back pressure?

If it's new ie still under warranty take it back to where it was fitted, tell them what you're experiencing and ask them to have a look, these outfits are made (or broken) on their reputations for quality product and after-sales care

[colin1]

Driving home tonight when at low revs it hesitates to accelerates and makes a chugging noise in the exhaust then it clear and return to normal ? Possible exhaust blockage ? It's a new exhaust well a few months old and it a 2.0 16v engine red top gsi!

Some things to consider other than your exhaust

Fuel filter
Sticky or fouled injector(s)
Distributor cap/rotor arm issues usually manifest themselves at low revs
Coolant temp sensor heading south would normally let you know at low revs too