randy ransome

Could someone tell me what this part is. I was looking at my 95 Z and saw it but it's not on my 91 Z.
It's own the front drivers side next to vacuum canister.

-=Jeff=-

I believe that is the A.I.R. pump, if your 91 has headers that is probably why it is not there

mine is in the attic

randy ransome

Thanks Jeff, yea the 91 has headers. I guess that's some emissions junk I don't need down here in MS, thank God.

blownrunner

It adds air to the exhaust so that the cats will heat up faster and work sooner. I pulled the fuse to mine: I think that by adding air to the exhaust the O2 sensors get fooled and the engine then runs rich, which is why I suspect all the smoke from the exhaust when you first put your right foot down.

WydGlydJim

Hmmm..I would talk to an expert about that.....another reason they add fresh air to the exhaust is to completely burn remaining unburned hydrocarbons in the exhaust...you could be sending too much unburned emissions to your cats, and thus giving them too much to handle thereby clogging them up..cars past about '78 can have some unintended bad consequences to removing emissions controls..may not be harmful at all, but might be worth a check.

mike100

The pump only runs for about 90 seconds to two minutes at first start in the morning- maybe a bit longer if the engine is really cool. If you have headers w/ air injection, you will get backfires until the air inj event ceases. I pulled the plug on the air pump until I had catalysts re-installed.

VetteMed

It runs only long enough to get the cats warmed up and operating efficiently. The LT1 uses a similar system, and until I disabled it on my TA with longtubes, the cold backfires were occurring regularly.

cvette98pacecar

I have three complete systems if anyone is looking for parts to keep their Z EPA compliant.