2001 with 94,000 miles. Car is very slow and makes a sound almost like a jet engine when you accelerate. I have changed intake gaskets, airbox and checked all coils/plugs which are firing. I opened blanks on cats also to see if would run better without any luck. Any body had this problem? (and fixed it!)
Thanks

 

What is the condition of the timing tensioners and chains?
Have they been replaced?
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Thanks for reply.
Not by me but I had 3000 trouble free miles until I found water in left bank cylinders shorting out coils. No overheating or obvious leaks so I put this down to rain seepage. Situation is now car runs poorly with dry plug apertures. Seems as though there is something fundamental wrong, but idle is as smooth as factory fresh car. No codes show which makes me wonder about computer

 

Have you fixed it so no water can now get in and also changed the coils? They are probably damaged. (You can buy a tester if you wish.)

 

Thanks again for help but had a sneaking feeling it wasn't timing related because of the smooth way it turned over. Since last message car got so it wouldn't run at all and I had all but decided to list for parts. Just out of "last chance saloon" I sliced the exhaust just south of the cat converter on the side I had the water in the plugs and would you believe it ran immediately. I poked around with a rod inside the open cat and to my surprise found it completely empty. One previous lady owner did not suggest "modifications of this nature" so I delved further and noticed that the center mufflers as I thought had obviously overheated. Could it be they are in fact the cats on this model 2001? I suppose I should say its more good news than bad but I am really confused.

 

Cats are between the O2s.

On mine, sloping tubing and you really cannot miss the cats.