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Popping upon acceleration issue

Mo Imzi

New Member
Good morning y'all. My 92 GT has been popping every time I accelerate and I cannot figure out why. I got the car straight piped and then the issue started. It also pops more at lower RPM and lessens a lot near higher RPM. Furthermore, if I gently accelerate, it barely pops at all. I think that it might be the hose from the smog system that attaches to the H pipe. It was cut when we removed the cats and now it just hangs. Do y'all think this is the issue or something else?
 

broncojunkie

Well-Known Member
First thing I would check is throttle position sensor. You should probably remove that thermactor pipe, though. They tend to leak and you will have an annoying exhaust leak... even if you cap it. You can simply cut the ends off (where they attach to the back of the heads), flip them, and bolt them back on. You're simply capping off the ports on the back of the heads. A little red rtv will help keep them sealed up.
 

Mo Imzi

New Member
First thing I would check is throttle position sensor. You should probably remove that thermactor pipe, though. They tend to leak and you will have an annoying exhaust leak... even if you cap it. You can simply cut the ends off (where they attach to the back of the heads), flip them, and bolt them back on. You're simply capping off the ports on the back of the heads. A little red rtv will help keep them sealed up.
Thank you so much! Will I need to remove anything else related to the smog system and reroute the belt if I cap the ports?
 

broncojunkie

Well-Known Member
To be honest, it's been a long time since I've done it. On my 88, the smog pump was already gone. I do know they tend to go out and I've heard aftermarket replacement pumps are junk. If you're not required to have it where you live, I'd suggest pulling it. Just keep everything in case you ever want to put it back on.

You can pull the pump off and get a shorter belt. You can also delete the egr if you like. There aren't any performance gains but it cleans up the engine bay and eliminates another failure point. You can make a simple egr block-off plate. You may get a check engine light but I think they make a part for that.
 

347HO

Active Member
Popping in the exhaust during accel is almost always fresh, cold, air entering the hot exhaust.
Due to your recent maintenance... I'd look at it.

2nd common reason is too lean... Probs not due to your recent maintenance.

3rd common is valve train issue... Probs not due to your recent maintenance.

Good luck
 

Mo Imzi

New Member
Popping in the exhaust during accel is almost always fresh, cold, air entering the hot exhaust.
Due to your recent maintenance... I'd look at it.

2nd common reason is too lean... Probs not due to your recent maintenance.

3rd common is valve train issue... Probs not due to your recent maintenance.

Good luck
Thank you, I will keep that in mind!
 
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