What kinda symptoms is when O2 Sensor is bad

Slow5.0 · Apr 24, 2004

I still trying find out whats wrong with my car , do you guys ever had bad O2 Sensors and what kinda symptoms are when O2 is bad

Nagash01WS6 · Apr 24, 2004

Mine felt like the car was misfiring... the car may also smell VERY rich.

Slow5.0 · Apr 24, 2004

Mine looks like misfiring , BUT it's runing TOO LEAN , ( my friend installed on right O2 hole Wide band sensor or what ever you call its too lean , 14.7 on WOT and 18s on idle or cruising

BlackVert · Apr 24, 2004

Seth5.0 said:
I still trying find out whats wrong with my car , do you guys ever had bad O2 Sensors and what kinda symptoms are when O2 is bad

wouldn't you get a check engine light if the o2 sensor was bad?

Venom351R · Apr 24, 2004

Black96VertGT said:
wouldn't you get a check engine light if the o2 sensor was bad?

Yeah usually. I still have the stock ones on, there 117,000 miles old and I think there due for a change Acutally Im replacing them in the next week or two. I do get a check engine light as well such as when Im cruising along in 4th gear and as soon as I hit 1500 RPM's the light comes on, after I get obove 2000 RPMs the light goes out.

Nagash01WS6 · Apr 24, 2004

Seth5.0 said:
Mine looks like misfiring , BUT it's runing TOO LEAN , ( my friend installed on right O2 hole Wide band sensor or what ever you call its too lean , 14.7 on WOT and 18s on idle or cruising

wow... should be around 13.0 at WOT and 14.7 at idle.

Black96VertGT said:
wouldn't you get a check engine light if the o2 sensor was bad?

Yep... it should.

Why not try a KOEO test and see if you get any codes?

Slow5.0 · Apr 25, 2004

Nagash01WS6 said:
Why not try a KOER test and see if you get any codes?

KOEO here we go , I just wanna make thread about what I find with KOER(key on, engine runing)
I got two codes
311 AIR system inoperative during KOER (Bank number 1 with dual heated oxygen sensors)
314 AIR system inoperative during KOER (Bank number 2 with dual heated oxygen sensors)

What this mean, and I don't have check engine light on

302fordracer · Apr 25, 2004

pretty sure the check engine light would be on if the car had a bad o2 sensor...it being part of he car's computer the chip should recognize a fault. No one has mentioned also that a faulty o2 sensor can eventually cause catalytic converter failure.

Venom351R · Apr 25, 2004

302fordracer said:
pretty sure the check engine light would be on if the car had a bad o2 sensor...it being part of he car's computer the chip should recognize a fault. No one has mentioned also that a faulty o2 sensor can eventually cause catalytic converter failure.

Not a problem when you dont have cats to begin with

SexyStang1994 · Apr 25, 2004

302fordracer said:
pretty sure the check engine light would be on if the car had a bad o2 sensor...it being part of he car's computer the chip should recognize a fault. No one has mentioned also that a faulty o2 sensor can eventually cause catalytic converter failure.

Catalytic what????

I love Florida....

AIR system is to heat up your cats... dont know how the computer would detect that fault though.

swingline · Apr 25, 2004

My O2's were bad and I did not get a CE light.

BlackVert · Apr 25, 2004

SexyStang1994 said:
Catalytic what????

I love Florida....

AIR system is to heat up your cats... dont know how the computer would detect that fault though.

According to my Haynes repair manual:

The AIR system forces air down into the exhaust manifolds while the engine is warming up to oxidize the hydrocarbons and carbon monoxide created by the rich running conditions during warming up. 94 and 95 models have a mechanical system, 96+ operate with an electric pump.

At least that is what my Haynes repair manual says about it.

ProKiller · Apr 25, 2004

O2 sensors are two in one deals. they are temperature reading and air/fuel ratio. they could be bad. get an ohm meter and test the resistence. it should be around 6 @ 68* ambient temp.

mo_dingo · Apr 25, 2004

You are getting codes for the AIR system (smog pump, etc), not the O2 sensors. Basically, the O2's are functioning properly, and telling you that something to do with the AIR system is bad.

Unless BOTH of your O2 sensors happened to fail simultaneously, which is possible.

Have you checked fuel pressure, spark, vacuum & compression? That will remove most of the likely suspects out of the equation.

The AIR system is only supposed to work for the first 20-120 seconds of car operation. After that, it is shut off (supposed to shut off).
Scott

Slow5.0 · Apr 25, 2004

I thisnk this is like 100th time I said , I check , clean and change EVERYTHING
ECT , IAC , IAT , MAF , TPS , Ignition Module , All spark plugs , wires , distributor cap , rotor , INJECTORS , air filter , fuel filter , fuel pump, O2 sensors , PCM , CCRM , everything , fuel pressure is 38 just like before , compression is good (137-150psi) timing is like before , everything looks normal but still runing too lean , looks like misfiring, I mean everithing , there is no vaccum leak between Upper and lower intake and lower to heads , I don't know what to do
I didn't check vaccum with Vaccum tools , I check for vaccum leak but no leak

BlackVert · Apr 25, 2004

Seth5.0 said:
I thisnk this is like 100th time I said , I check , clean and change EVERYTHING
ECT , IAC , IAT , MAF , TPS , Ignition Module , All spark plugs , wires , distributor cap , rotor , INJECTORS , air filter , fuel filter , fuel pump, O2 sensors , PCM , CCRM , everything , fuel pressure is 38 just like before , compression is good (137-150psi) timing is like before , everything looks normal but still runing too lean , looks like misfiring, I mean everithing , there is no vaccum leak between Upper and lower intake and lower to heads , I don't know what to do
I didn't check vaccum with Vaccum tools , I check for vaccum leak but no leak

huh. maybe it's the computer?

Slow5.0 · Apr 25, 2004

Black96VertGT said:
huh. maybe it's the computer?

Do you see my post before yours " PCM , CCRM "
I try that and same thing nothing change

Venom351R · Apr 25, 2004

mabye its your 02's

J/K

Slow5.0 · Apr 25, 2004

Stop joking , this is serious problem , I can't drive my Stang on job or on the track and summer time is here

mo_dingo · Apr 26, 2004

You can rent a vacuum gauge at autozone. It's really easy. It will tell you if you have a vacuum leak, or if one cylinder isn't performing properly.

The computer seems to think that the AIR system is bad. Have you checked everything there? Your smog pump may have taken a dump!
Scott

What kinda symptoms is when O2 Sensor is bad

Slow5.0

Active Member

Nagash01WS6

New Member

Slow5.0

Active Member

BlackVert

Venom351R

Nagash01WS6

New Member

Slow5.0

Active Member

302fordracer

New Member

Venom351R

SexyStang1994

swingline

New Member

BlackVert

ProKiller

mo_dingo

Slow5.0

Active Member

BlackVert

Slow5.0

Active Member

Venom351R

Slow5.0

Active Member

mo_dingo

Similar threads

What kinda symptoms is when O2 Sensor is bad

Active Member

New Member

Active Member

New Member

Active Member

New Member

New Member

Active Member

Active Member

Active Member

Similar threads

Privacy & Transparency

Privacy & Transparency