O2 sensor faulty?

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Mar 26, 2008 | 03:31 PM

blackhawk66

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Staging Lane

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From: Southampton,England

O2 sensor faulty?

Other than a scanner is there a way of telling if an O2 sensor is bad? as I have a 95 T/A that's stock and it takes a little time to start and also sometimes smells rich. Also I have noticed poor fuel economy,averaging about 14 mpg.
Fuel here is £1.06 per liter!!!! and I need to sip rather than guzzle the motion lotion...

Mar 27, 2008 | 02:58 AM

LT1-DAN

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From: FLORIDA

My guess would be your problem is ignition, not o2 sensors.

Mar 27, 2008 | 03:09 AM

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Black99T\A

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sounds like an o2 to me, just replaced one on a pontiac montana, by far not a ta, but it was running rich and getting horrible gas mileage and it also threw a o2 code

Mar 27, 2008 | 03:35 AM

LT1-DAN

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O2 sensors have nothing to do with it "taking a little time to start"

Mar 27, 2008 | 03:37 AM

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Black99T\A

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could be alot of things, is it throwing a check engine light?

Mar 27, 2008 | 08:28 AM

James Montigny

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Quote:

Originally Posted by LT1-DAN

My guess would be your problem is ignition, not o2 sensors.

That's certainly possible.
Is it running rough at all once it gets going?

Mar 27, 2008 | 08:45 AM

fast92lt1rs

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From: San Diego, CA

Taking a little time to start could be a couple of things. Shut off your engine and check your fuel pressure. Then check it a few hours later with the engine off. It should not have changed that much. If there is a big difference you could have a faulty fuel pump or fuel pressure regulator. The fuel system should hold pressure for a long time. If there is a big change start by pulling the vacuum line off the regulator. If there are any signs of fuel there then it is leaking internally and needs to be replaced. Also, how many miles are on the car? O2 sensors should be changed by 100K or sooner. You might also need new plugs and wires. Is the opti original? Is the car giving you any codes?

Pete

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Mar 27, 2008 | 02:47 PM

blackhawk66

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Staging Lane

Joined: Dec 2005

Posts: 66

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From: Southampton,England

Thank you for all the replies, firstly the car has 26000 miles on it and once the car is started it runs fine except for crap mileage.There is no engine light on or any other indication of a fault, however I will add that the car only did 4000 miles in total last year with its previous owner so the car has probably been stood around alot.
I did notice today that when I booted it from a low speed whilst in a tunnel

there was a sudden 'pop' noise coming from somewhere but can't tell if was up front or from the exhaust because of the echo effect of the tunnel.I am going to change the oil,fuel filters and check/change the spark plugs to see if that fixes it.