It started about one week ago my 96 mercury cougar XR7 won't go over 35 mph it just revs to about 3000 rpm. I replaced the pcv and had a complete tune-up, also checked the transmission. What could it be ?

Best to let a shop listen to it. Free estimates

Hello Maria Lucio,

Best test & replace video I've ever seen...

96 cougar purge valve replacement Ask com YouTube Search

The whole search:
Ask com What Your Question

Rockauto parts price:
http://www.rockauto.com/en/catalog/mercury,1996,cougar,4.6l+v8,1198795,emission,vapor+canister+purge+valve+/+solenoid,4936
1996 MERCURY COUGAR 4 6L V8 Vapor Canister Purge Valve Solenoid RockAuto

No chips in keys for this year.

Did you recently replace a car stereo?

LOOK FOR PLASTIC ACCESS PANEL.FUEL PUMP UNDER THE PANEL YOU COULD HAVE 96 MERCURY COUGAR.WHICH YOU HAVE TO DROP FUEL TANK TO REMOVE FUEL PUMP.

any smoke coming out the tail pipe? is it black, carbon smoke? if so your catalatic converter is clogged. replace it.

You have a vacuum leak. Check PCV hose on passenger rear of engine. Stuck open EGR valve can also be the cause.

Check your local library for repair manuals...

My cougar does the same, it starts and then about 1 minute later (or so) the check engine light comes on and the car idles really high, with black smoke out the exhaust. It stays in second gear i think and it will not shift out of it. Max speed is 40 mph with the rpms screaming, it will go off after a long time but this is agrivating. I have a 94 mercury cougar xr7 3.8 ltr Any help please?

check pcv valve for failure/sticking

throddle postion senor maybe