Bad o2 sensor?

[JBDdsmer610]

I was wondering if my o2 sensor could be bad i just put new plugs in and the plugs i took out had less than 1000 miles on them and they were yellow. My car lags before it starts to boost then goes right to 14psi real quick I have no boost leaks i just did a test on it yesterday holds 14 psi for about 2 min. I have never replaced the o2 sensor is there anyway i could tell that its bad?

[DSMunknown]

Originally Posted by JBDdsmer610

I was wondering if my o2 sensor could be bad i just put new plugs in and the plugs i took out had less than 1000 miles on them and they were yellow. My car lags before it starts to boost then goes right to 14psi real quick I have no boost leaks i just did a test on it yesterday holds 14 psi for about 2 min. I have never replaced the o2 sensor is there anyway i could tell that its bad?

The CEL will light up when either of the O2 sensors fail. FYI you have two O2 sensors.

[JBDdsmer610]

I thought 1gs only had a front o2 sensor i do not have a rear o2

[DSMunknown]

Originally Posted by JBDdsmer610

I thought 1gs only had a front o2 sensor i do not have a rear o2

Nevermind. I thought you were a 2G guy.



Here, read this.

[JBDdsmer610]

I just called the dealership all the recalls are closed on my car. But its weird its like im running lean, there is some minor detination on the pistons. I just cant figure it out because im not tunning with anything so i shouldnt be running lean.

[Jeff822]

Take it to strauss yo!

[Quasimondo]

Have you experienced a dramatic decrease in fuel economy? When you say your turbo lags, around what rpm does it begin to spool up? Does the engine stumble off boost?

[Boostin240]

yellow plugs? doesnt seem that good, any pics?

[JBDdsmer610]

Yes fuel economy has decreased. It starts to spool about 2800 to 3000 depending on how hard i hit the gas, but as soon as it starts to spool it laggs and goes to 12psi then boggs. What do you mean stumble off boost?

[JBDdsmer610]

Attachment 70918

[spyderturbo007]

This might help. More information than you ever wanted to know about spark plug reading.


http://www.usaimports.co.uk/Mopar_Te...ug_Reading.htm

[Quasimondo]

Originally Posted by JBDdsmer610

Yes fuel economy has decreased. It starts to spool about 2800 to 3000 depending on how hard i hit the gas, but as soon as it starts to spool it laggs and goes to 12psi then boggs. What do you mean stumble off boost?

When the turbo is not spooled up (partial throttle cruising where the intake doesn't see any pressure), does the engine feel like it's sputtering or stumbling when you increase the throttle?

When an oxygen sensor fails, it no longer produces any voltage for the ECU to see. Without this signal voltage, under closed loop operation, the ECU will assume that the engine is running lean and will add fuel to compensate. Since it's not getting any feedback from the oxygen sensor, it will continue to add fuel. If you have a logger of know somebody who has one, you can also check the O2-R reading to see if it cycles between .10 and .90 volts. If it barely generates any voltage, then your oxygen sensor may be failing.

[DSMunknown]

Armando, why is it exactly that the 1Gs only have one O2 sensor?

Obviously, with most modern-day vehicles, there are two O2 sensors (one before the catalytic converter and one after). The first sensor reads the gas particles, and more importantly the second one reads the gas to detect if there are any changes in the gas particles (because there should be). This allows the ECU to recognize when there is a problem that needs to be fixed.

Hence, my question.

[delta448]

I thought the 2nd sensor was only to determine how effective the catalytic converter is. Hence the CEL when you remove your cat.

[spyderturbo007]

Originally Posted by delta448

I thought the 2nd sensor was only to determine how effective the catalytic converter is. Hence the CEL when you remove your cat.

Correct.

[DSMunknown]

Originally Posted by delta448

I thought the 2nd sensor was only to determine how effective the catalytic converter is. Hence the CEL when you remove your cat.

That's why I said there should be a change. If there is virtually no difference between the two readings, then generally it means that the catalytic converter needs to be replaced to pass emissions tests (or that you have simply removed it and the ECU reads that as being the same thing).

[JBDdsmer610]

YEs when the turbo is not spooled up just cruising when i give it gas it studders then goes to 10 psi then studders again and goes to 12 psi almost like it misses but i think its the o2 sensor

[Quasimondo]

Do you have access to a logger to verify your O2 sensor is properly working? I'd hate for you to swap out a part if that's not the problem. If you don't have a datalogger, an alternate method involves using a multimeter. If you remove the passenger side kick panel and blower cover, tucked in with the wiring is a small female spade connector. This connector splices into the output for the O2 sensor. Connect the positive probe of your multimeter to this connector, and connect the negative probe to a good chasis ground.

Set the mutimeter to the closest it will go to a 1-volt reading and start your car up. Rev the engine a few times, and monitor the multimeter. It should jump around between 0 and 1 volt. If it doesn't move, before you pull your O2 sensor, check your base timing. Symptoms of your base timing being improperly set is rough running when cold and hesitation when you get on the throttle.

The connector behind the kick panel is a bit tough to find, so here's a link to help you:
http://www.vfaq.com/mods/wayback/Bra...l/find-o2.html

I can't stress enough that you make sure the O2 sensor is bad before you burn $70 from your wallet and scrape all the skin off of your knuckles trying to remove it.

[JBDdsmer610]

I actualy had my buddy put his snap on scanner on it today. The only thing the scanner said was if o2 was under 400 there could be a possible vacume leak. but o2 volts were like 390. well i did some experimenting the rest of the day i let the car cool down for a bit. I start it back up like half hour later i get in it and romp on it a little and it didnt bog down or anything. then one i hit opp temp it laggs again. I dont think i have any boost leaks i get 20psi of vac all the time. and i already did boost leak test sevral times.

[Quasimondo]

Well, replace the O2 and let us know if that fixes the problem.