what happens whemn the oxygen sensors go and no codes?

hgallegos915 · Post by **hgallegos915** » December 3rd, 2005, 3:01 pm

hmm trying to figure it out still nd well its fuel related. so.. ok how does ones car react when oxygen sensors go? what about the idle control unit underneath the throttle body? my car will drive fine when cold... a few minutes later little by little it starts to missfire. I guerss basically the question im trying to answer is what does a car do when the oxygen sensors are bad? I pulled them out and they are black , cleaned them but well yeah.

lakersfan1 · Post by **lakersfan1** » December 3rd, 2005, 6:24 pm

O2 sensors are always black. Raw exhaust is blowing on them.

hgallegos915 · Post by **hgallegos915** » December 4th, 2005, 2:30 pm

yes but well trying to be a bit more clear "what does an automobile do when these devices are bad" ? anyone?

lakersfan1 · Post by **lakersfan1** » December 4th, 2005, 2:43 pm

When they're broken, the ECU reverts to a pre-set fuel map that usually makes the car run really rich.

hgallegos915 · Post by **hgallegos915** » December 4th, 2005, 3:50 pm

thanks

GQ084 · Post by **GQ084** » December 5th, 2005, 2:26 am

9/10 you will get the red light of death (aka CEL) so its porbably not a oxygen sensor problem.
Whens the last time you had a tuneup? My car misfired, irradic idle until i got tuneup.
Question, car driven cold? What do you mean, you just hop in and go...

Putting on your seatbelt....5 seconds
Not waiting for car to heat up...20 seconds
Getting to your destination...30 minutes
Waiting for your car to get fixed....6 hrs wait time + labor.
Wishing you spent 1-2 minutes letting your car warm up.....priceless.

ikarus1 · Post by **ikarus1** » December 5th, 2005, 10:26 am

hgallegos915 wrote:yes but well trying to be a bit more clear "what does an automobile do when these devices are bad" ? anyone?

1. little to no feedback to ECU on mixture (ie: usually rich) so it runs open loop (preset fuel maps based on TPS, EGT, VAF/VAT and MAP sensors)

2. usually CEL with codes 17, 24, etc related to EGO sensors

3. reduced economy (worse fuel mileage)

4. increased fuel washing oil off cylinder walls / fuel into oil leads to increased chance of wear and decreased oil life due to presence of more
fuel in oil. 1-2% in the crankcase is BAAAAAD

hgallegos915 · Post by **hgallegos915** » December 5th, 2005, 10:37 am

im starting to blame iton the ditry, im going to go get yet another exchange ..i hate checker.. and I hope its the disty.

hgallegos915 · Post by **hgallegos915** » December 5th, 2005, 12:14 pm

I give up, shops dont wanna help, checked doesnt wanna help, no one knows whats wrong..im selling it for 800 dllrs or best offer or if it does not sell, pulling engine and sending it straight to a dump yard. Ill take pics as it is being towed to the yard if it doesnt sell.. what a waste of money.

hgallegos915 · Post by **hgallegos915** » December 5th, 2005, 12:15 pm

I give up, shops dont wanna help, checker doesnt wanna help, no one knows whats wrong..im selling it for 800 dllrs or best offer or if it does not sell, pulling engine and sending it straight to a dump yard. Ill take pics as it is being towed to the yard if it doesnt sell.. what a waste of money.

hgallegos915 · Post by **hgallegos915** » December 5th, 2005, 12:15 pm

I give up, shops dont wanna help, checker doesnt wanna help, no one knows whats wrong..im selling it for 800 dllrs or best offer or if it does not sell, pulling engine and sending it straight to a dump yard. Ill take pics as it is being towed to the yard if it doesnt sell.. what a waste of money.

Nd4SpdSe · Post by **Nd4SpdSe** » December 5th, 2005, 3:19 pm

I know when my O2 sensors were going, I was getting a slight misfire, I didn't even notice it with my untrained ear, curtklze pointed it out, but i also had no CEL codes indicating it either. It's possibly that they would be bad, but not bad enough to give a code. Also, you have a KF, can you get CEL codes with a KF ECU?

lakersfan1 · Post by **lakersfan1** » December 5th, 2005, 4:51 pm

Are you running KF ECU and JE50 VAF? If you're still running that KLDE ECU, I'd say you're running way too rich for too long.

GQ084 · Post by **GQ084** » December 5th, 2005, 5:24 pm

how much for engine?

hgallegos915 · Post by **hgallegos915** » December 5th, 2005, 5:29 pm

hmm dont want to jinx myself... but well here it goes.. I THINK i found the problem.. ok underneath the dash theres a ton of wires (harness to the fuses) I had melted wires touching.. i think it may have friend my kf ecu..not sure yet. Anywho i corrected the wires and am still going to the shop to have that rewired. I put on the k8 ecu and it runs fine. May missfire from time to time so thats a good indication o2 sensors. Whats weird is that it runs perfectly with k8 ecu. Anywho.. Also the fuel pressure regulator NEEDS that solenoid..it was just getting vacuum causing me to run lean . I still dont trust the car ..been driving around my neighboorhood for a few hours and i get missfire when i turn..indicating the wires underneath need to be fixed. wish me luck please. If i do sell it id sell the whpole car for 800. including good new engine and tranny.. thats if i cant fix it.