I have a 99 ford explorer and when i step on the gas my air blows and when i slow up i can barley feel it! when i go over a bump it comes on and when i stop it goes off? help me!

replace your idle air control valve, common on fords

check all the mount bolt to your transmission.

did you hook everything up right? Im not doubting your work but sometims it happens

had same problem on my 99 explorer---map sensor in air cleaner inlet was bad--about 75 to 100 bucks at junkyard RS

check behind the glove box there is an air intake there and alot of times things will fall out of the glove box and plug it up, also underneath where the wiper arms fo sometimes it will get plugged with leaves this is where your fresh air intake is at.... the one inside the car behind the glove box is where the air intake for max a/c is.

You may have something clogged in the fins of the blower motor. Check that first. I'm always pulling plastic grocery bags out of them.

You have a vacuum leak either under the dash that works the air conditioner or under the hood.

This could be bad compressor clutch or a leak

You mention no check engine light, and all the work you've done leave one solution; Your catalytic converter is clogged.

When you replace you catalytic converter your issues will cease. This is a very common problem, and a simple fix.

I hope this information helps and I wish you luck with your repair.

We had a 1997 Ford Explorer that did something very similar. We thought the transmission was going out, but it was the exhaust manifold gasket. Cost us a couple of hundred at the dealer to get it fixed, but that was a few years ago.