strange idle

[Foster5991]

Hey, sorry if this is in the wrong section, I'm kind of new here
I have a series 1 vt v6 commodore, factory manual
A few weeks ago I had genie extractors installed with a high flow cat and a 2 and a quarter inch catback exhaust, ever since then I've had a problem where when I put the clutch in to either come to a stop, or maybe coast over a speed bump, the revs shoot to 2000rpm and stay there until I come to a complete stop, at which point they drop to standard idle, or sometimes idle high at 1500rpm at which point the engine light comes on, than it drops to standard idle and the engine light goes off, I've haven't been able to get the fault code yet but does anyone have any advice that could fix this?
It was recommended that I change the tps, which I did and it still does it, I haven't had a chance to replace the iac, could that be the problem? Is there any chance it's the egr on the extractors considering it started when they were installed? Cheers

 

[lowandslow]

Would def look at the EGR as it's the only thing that has been touched like you said. Def check and clean the IAC aswell.
Do an ECU reset aswell. (Just disconnect the battery or pull the main fuse for 10 minutes.)

 

[Foster5991]

Any recommendations on how to fault the egr? Before spending money on it
What would be the best way to remove/clean the iac, because I saw a few things online where people kept breaking theirs removing them
Ecu reset was performed yesterday and no luck, thanks buddy!

 

[lowandslow]

Remove TB then remove the IAC would be the best way if your scared of breaking it. Can't see how it would break upon removal. They are quite a snug fit when re installing them so do the screws up evenly.
Wouldn't have a clue on the EGR.

 

[Foster5991]

No worries, ill give that a shot and maybe swap the iac and egr from my donar car tomorrow and see if I have any luck
I tried bridging port 5 and 6 on the scan tool plug to check for engine codes and only got 12 (system pass) so tomorrow at work I might try get a proper scan tool on there and drive it to try log the code, thanks for the help, I'll probably be back tomorrow with an uodate

 

[Foster5991]

I swapped the egr and found that the egr I had on had no gasket, the problem is now fixed, unsure of whether it was the whole egr, or just the gasket though