1993 twin-turbo. I unplugged the electrical connection to the airpump. The "moo" noise immediately stopped. The motor ran quieter and smoother.

Two questions:
Will this cause any long term harm to the engine?
Will performance be adversely affected in any way?

 

Questions for you...do you have any mods--list if so...Do you still have a cat and ACV?

 

just fyi, search for this air/smog pump removal lots of threads that'll give you the consequences of removing it. do you just plan on unplugging it or are you going to remove it entirely?

 

Yes. Pettit Racing did a "turbo upgrade"; which included removing the "air box" and exchanging it for direct outlets with filters on them. The airpump outlet that had gone to that airbox may have had a noise suppressor on it that fell off causings that awful noise. They also replaced the down pipe with a straight thru type that eliminated the (clogged) secondary cat.

 

Sorry, I reread your question. The main cat is still there. What ia a "ACV"?

 

I plan to leave it there, as is, unplugged!!! But, I will do whatever if advice says this is wrong.

 

It won't harm anything to leave it in place but unplugged.

 

yup, was debating this since my airpump's wires burned off, but i ended up just putting it back together. but the car did run fine for the time that i did spend with it unplugged.

 

The car will overfuel at idle and foul the plugs.

Do not leave the air pump unplugged, it is there for a reason. If you want to eliminate it, you have to lean the car out at idle using a PFC or similar management system.

 

Some people say it will not idle as well and that there are a few other small things that you wont work right. But in my experiance with the 10 or 12 fd's that I have done this too there has never been a differnce at all. But I dont know everything.

 

Harumph, if you still have the mazda catalytic converter in place underneath the car, or any cat for that matter, You should leave your airpump wiring hooked up. If you do not you will melt another cat. You may unplug this airbox side air hose. The stern side air pipe should be left connected as well as the metal pipe to the standard cat.

 

If you still have the main cat, you should leave the airpump plugged in, or the cat has a high chance of clogging.

I run a midpipe and recently unplugged my airpump with the wideband hooked up to see the effects. It idles at 11.5 AFR either way, but with the airpump unplugged you are not getting air pumped into the exhaust manifold, so it is actually running leaner with the airpump unplugged. WOT is unaffected.

And I was surprised when the car basically idled and drove the same, if not smoother without the airpump.

I have an rx7.com chipped ECU BTW.

 

I unplugged mine and like you had no ill effects on idle. The Pettit CAI had a noise surpressor to muffle the moooooooo effect when eliminating the stock air box so it may have dropped off or became disconnected. If you still have the main cat it will speed up the clogging process but can be changed out with a high flow. With the down pipe and a hi-flow cat with any kind of cat back and the Pettit CAI you will have to limit your boost to 10 psi and may have trouble doing so with the high flow cat. The main cats are easy enough to find in the for sale section cheap so leave it unplugged and if you main cat clogs just solicit one from someone on the list. As long as your idle is fine your ahead of the game.

 

Ok so to set the record straight here...

You can unplug the cat safely as long as you have a Highflow Cat or a midpipe correct?

 

Wat if the OEM cat converter is changed into a Bonez HF? Will it clog or melt or is it resistant?

 

Just curious how does the air pump cause it to run leaner ? ? ? ? ? The air pump injects air in at the main cat (far after the o2 sensor) not any where into the intake tract and the ECU drops the clutch on the air pump after 3k WOT or not. Where did you get this information ? ? ? ?

 

Holy Crap that a rich idle!! I just tuned my idle down from 10.8/11.5 to 13.2. But I have a power fc so I am able to do that. The car runs way smoother at idle and I don't kill people around me with the exhaust fumes. Running that rich at idle will foul your plugs quicker.

R.K.

 

Keep in mind you can unplug the air pump as long as your
1) not concerned about passing emissions
2) could care less about your main cat deteriorating faster than normal
3) not worried about your idle if it becomes lumpy.

You need to be concerned about adding a high flow cat , mid pipe or resonated mid pipe if you
1) already have a down pipe &
2) cold air intake &
3) aftermarket cat back
as you will need to control your boost and limit it to 10 psi and prevent boost creep by what ever means necessary