Quote
its a 4x4 automatic they have checked the tranny and said that was working like its supposed along with everything else..i have gone to past forums who seem to have had the same problem and most seem to be a clogged CAT,or issues with timing belt but again they disconnected it and the car ran no better, the timing has been checked countless times.


Go back and check the cat converters again. Yes, plural, there are two of them. One is located right on the exhaust manifold. This is the cat that clogs most often. I'll bet if you pull it off the exhaust manifold you'll find the input screen clogged. And you may also find a crack in the exhaust manifold.

The 2nd cat is located directly under the driver's side. It does not clog often but sometimes it breaks down internal and clogs the exhaust.

Your low manifold vacuum readings are a big indicator that something is clogged in the exhaust system. Have your mechanic check it again.

1998 Sportage - Gone.
2004 Honda Civic Coupe.
2007 Suzuki Grand Vitara - She got it.