Car feels sluggish

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Feb 27, 2008 | 10:51 AM

brucelee

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From: Atco, New Jersey

Car feels sluggish

Hey guys im trying to track down some issues with my 99 z28 m6. The symptoms include;

Slight power loss
Poor gas milage (about 200 per tank)
occasional high idle
occasional hesitation in the mid rpm range

Im open to suggestions

Feb 27, 2008 | 10:56 AM

qwk93ta

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From: Fairfield, Ohio

Are getting any codes? Have you done a tune-up on the car? Change the fuel filter?

Feb 27, 2008 | 11:05 AM

brucelee

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From: Atco, New Jersey

tune up was done about 20k ago car now has 101k. fuel filter done 10k or so ago. no codes.

Feb 27, 2008 | 11:08 AM

Gun5

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From: Tomball (H-Town), TX

Quote:

Originally Posted by brucelee

tune up was done about 20k ago car now has 101k. fuel filter done 10k or so ago. no codes.

sounds like a O2... bad mileage sluggish

Feb 27, 2008 | 12:01 PM

brucelee

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Quote:

Originally Posted by Gun5

sounds like a O2... bad mileage sluggish

that would be the front o2's correct? also would they be considered upstream?

Last edited by brucelee; Feb 27, 2008 at 12:16 PM.

Mar 4, 2008 | 09:24 PM

sdm1234

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From: Holland Twp/Milford, New Jersey

it could be a bad PCV valve causing all of these symptoms. it may be the EGR valve, as well. it could be a vaccuum leak, causing occassional high idle. a hesitation at midrange could mean a bad spark plug wire. it may also mean preignition. have you noticed the coolant temp during the hesitation? that could do it. it may be an 02 sensor causing bad mileage and sluggishness. it could also be a faulty fuel injector. i sure hope you don't have burnt valves, causing weak compression. it could also be a faulty TPS sensor too, although this is uncommon. it may be a clogged catalytic converter, as well.

Mar 5, 2008 | 03:09 AM

waldershrek

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From: NY

Yes the front O2's tell the computer how rich or lean your exhaust is and adjust the fuel and spark accordingly to compensate. The rear O2's (after the cats) determine by sniffing the exhaust how well the cats are working and will set an emissions code if they are not working up to specs.