Mk4 golf major idle issue

[Papasquidge]

Hi guys need your help.
So ive been given a 99 golf and told if i can fix it i can keep it. So my issue is it has a major idleing problem where it bounces from 1000 to 2000
Constantly.
So work done before i started new maf sensor new crank sensor new cam sensor. I noticed it had a moajor misfire so changed coil leads and plugs misfire sorted but still iratic idle have cleaned throttle body still the same also the exhaust glows red hot?
The throttle body also pops when accelerating any help and advice guys?

[Rob69]

I'd get a compression test done next, suspect a burnt out valve.

[cbrpaul]

A mate had a similar issue with a focus, turned out the cat collapsed , blocking the escape of gases and causing the exhaust to get very hot,,,,,

[Rob69]

Good point - loads of exhaust back pressure.

A mate had a similar issue with a focus, turned out the cat collapsed , blocking the escape of gases and causing the exhaust to get very hot,,,,,

[niall campbell]

or a collapsed baffle in an exhaust

take off cat & have a look , or disconnect exhaust at exhaust manifold and turn her over and apart from lots of noise ...................... does it help ?