1999 Buick Lesabre PO172 system too rich

SJDEMURE

MEMBER
1999 BUICK LESABRE
6 CYL
FWD
AUTOMATIC
172,000 MILES

Took car to auto repair place, said that my O2 sensor was bad. Had that replaced, cost me $150 bucks. But Check engine light comes back on after a few miles driven. Went to Autozone, they game me a free computer scan. Said the code was PO172 system too rich ( Bank 1). Store attendant said that my engine might be getting too much fuel. But car is slow to accelerate as soon as I put my foot on it. I could be at a red light, fullly stopped, then once I step lightly on the accelerator, I get a very delayed acceleration. I need some suggestions here. I dont want to go broke trying to figure this out.

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Possible causes include a bad O2 sensor, excessive fuel pressure (bad fuel pressure regulator or plugged return line), leaky fuel injectors, dirty air filter or restricted air inlet, or a defective coolant sensor that prevents the engine management system from going into closed loop mode

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Wednesday, June 11th, 2008 AT 12:31 AM

SJDEMURE

MEMBER
2 POSTS

Could the problem also be an intake manifold gasket problem?

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Wednesday, June 11th, 2008 AT 12:39 AM

RASMATAZ

MECHANIC
75,992 POSTS

Intake gasket leak will lean the mixture and the computer will throw fuel at it to compensate-You can check for leak with WD40 and spray between the intake manifold flanges when it hits the leak area the idle will smooth out-

You need to check the items I've mentioned earlier.

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Wednesday, June 11th, 2008 AT 4:06 AM