Codes Guru's needed
 

I have the following codes and SES light on.
PO130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
PO131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
PO171 System too Lean (Bank 1)

Theses codes were thrown b4 I put in my Intense PCM. I changed Fuel filter cleared codes and they returned a week later. Now I have changed PCM codes came back I then changed front O2 Sensor.

These Codes get thrown and SES light comes on when at Highway speed and going to pass someone. Car seems to buck and then cick in and go. Car seems to run fine and idle fine until yesterday. Yesterday after doing some Highway driving and getting back to the city, it seems like at every stop light when I try to go it bucks and seesm like it wants to stall. Yesterday was 30+ degrees Celcius with high humidity.

Just hoping someone here can give me some clues before I take it into the dealer to be scanned.

Thanks in advance.

If you had an exhaust leak, throwing off the sensor, I wouldn't expect to see the malfunction fault. Only the lean.

I suspect a wiring problem between the O2 and the PCM, given the fact that it did this with two different PCM's.

Someone with a 2000 FSM can give you the pinout from the O2 to the PCM harness for checking the resistance and voltages.

Did you get a new PCM or did you send your original in to be reflashed??
If its the same computer then possibly the computer is bad
Otherwise check all the 02 wires and make sure there isnt anything suspect there..
It is also posslibe to have a defective sensor.

Could I try this?
 

What about the MAF could I try to clean that or can it be cleaned? Just wondering as it seems to throw the code when I step on it to pass on the highway and did not throw it from stomping on it in the city? Could the new K&N have thrown some oil or something on the MAF sensor? Should I take it in to get the exhaust checked for any leaks?

Thanks

Your MAF has nothing to do with it. You have an O2 Malfunction code.

Thanks
 

Thanks PontiacDad

I guess I will take it in then as I have no idea on how to do any checks for voltage this is way above and beyond me. This sounds like it will not be cheap to figure out CRAP.

Thanks

Re: Thanks
 

:?:

:lol:

Re: Thanks
 

look at the bottom of your sig will, he obviously just got confused...

Confused
 

Yep scrolled down to far thanks Will and Toastedoats. I just dred going to the dealer for this sort of stuff. Toastedoats sorry for not replying but yes it is 2 different PCM's I sent my old one back to intense.

Re: Could I try this?
 

When did you put the filter on in relation to your problem starting?

It could certainly be the trouble but there could be other causes. It's not uncommon to hear of this after a filter install or clean and oil. Excess oil could be picked up in the air stream and deposited on the MAF sensor. In that case the MAF will not read the incoming air correctly and will report much less air than is actually flowing, in that case you would certainly get a lean condition.

To clean the MAF, once your intake assembly is removed, you will need to remove the MAF screen. You will need to remove the circlip around the perimeter, you can do this gently with a small screw driver to pry towards the center. Remove the MAF screen by very gently prying and edge or two and wigling it out, the screen is somewhat solid but can be easily damaged.

Use a Qtip with Rubbing Alcohol to clean the MAF wire, be extremely gentle because it's a very small wire. If you need more details on this post back.

Otherwise, you could have melted a wire for your O2 sensor or it chaffed against something. Also, the sensor could be defective. If it does need repalcing, only use an AC Delco unit (AFS 109), other brand are known to be less effective.

Hope this helps!

Cheers,

You may find it easier to remove the MAF sensor for cleaning, rather than the MAF screen.

MAF
 

OK went out at coffee and removed MAF Screen upper electrode and lower looked ok. Although the upper one was black looking and lower was more grey. Got some 99 proof rubbing alcohol and a qtip. Had a couple shots of the rubbing alcohol to calm my nerves LOL. The upper electode is now grey like the lower one lots of black particles came off of it. I also left the Screen out is this ok??? Seems to run fine at WOT no hesitation. Will the codes clear themselves or do I have to get them cleared? I did make an appointment for tomorrow am at the dealer should I get them to read the codes and clear and see howw that goes??

Just also wanted to say thanks to everyone for all the help CHEERS to all of you!!

Mark

there is no REAL harm in removing the screen, mine is removed and i see no gain or harm.. Some people report a slightly rough idle with it out, but it all depends on the car and conditions.

I had a similar problem as yours that developed after I had replaced the O2 sensor. At certain highway speeds, intermittently it would act as if the engine stopped. Letting off on the gas, or stepping on it harder got things moving again. Idle was occasionally rough (acted like it wanted to die, then engine would rev up before settling). This started about a month after I replaced it. No codes were thrown at the time, and I could find no cause for it until about a month after that I got the same codes you did. I asked for a warranty replacement for the O2 sensor,. Replacing the replacement cured the problem.

I still believe you have an O2 problem. 2 of those codes had nothing to do with the MAF whatsoever. The MAF may have been part of your felt symptoms, but not those codes.

i agree 100% if you are throwing 2 O2 Sensor codes, you definately have a direct issue with the sensors or wiring to them

Thanks
 

Well I guess the only thing to do is to take it into the dealer and see what they tell me. Is there something I should ask them to do besides read the codes? It ran great all nght tonight and I did a ton of driving, but SES light is still on no hesitation at any red lights either. Do not get me wrong I did clean the MAF sensor like I was told by I think Foghorn and found some gunk on it but I have no clue if this fixed the problem. This is why I am here asking you the Experts and I greatly appreciate all of the help!!!!!!!! So what should I get them to check? My appointment is for 9:00 am. And once again THANKS!!!!!!!!

Mark

Try one thing before you resort to going to the dealer and shelling out cash. Disconnect your battery for 30 minutes to clear the codes. If the light comes back on when you drive it, take it to the dealer then.

Okley Dokley
 

Thanks for the response will I just cancelled the appointment and went out and disconected the battery. I thought that you could not clear codes on newer vehicles by doing this???

Mark

Re: Thanks
 

As Willwren suggested, you could reset the PCM by disconnecting the battery for half an hour though I'm not sure if this will clear the codes. If it doesn't, go to the dealer and have them clear the codes with a Tech II.

What we want to see next is whether the codes you previously experienced will be set again.

An oil covered MAF is a funny situation, in that state it cannot read the airflow correctly and under reports the Grams/Second of airflow to the PCM. This situation does not set an SES light but causes a cascade of problems. The PCM commands fuel based on the air it thinks is enetering the cylinders, obviously this is picked up by the O2 sensor as being too lean but in all likelyhood the PCM is unable to add sufficient fuel (it can add up to 20%) to bring your Air/Fuel Ratio into line.

I've seen this problem a few times previously and when you look at the MAF it doesn't look dirty but it takes very oil to inhibit its' ability to read airflow.

If your car is performing better after the MAF cleaning then that's great. But now you must make sure that was the problem and that it's not something else. You must have the codes in the PCM cleared and pay attention that they are not set again. If they're not set...then you're all set ;) ...but if they set again you'll have to dig deeper.

Hope it goes well.

Cheers,

codes reset
 

Well the 1/2 hour battery disconect worked, actually left it for like 1.5 hours. I will see if the codes or SES comes back and report back to everyone.

Thanks

Mark

Bank1 lean codes generally point to a vacume leak. One of the cheap plastic lines or a t fitting could have cracked and is allowing a leak to take place.

Just so you guys are aware, a problem at the MAF wiring can cause your fuel level sender to not work, as well as the O2. All that wiring runs inline for the MAF to the injectors to the MAP to the 02. If one gets messed up it can throw codes for the others. This is of course only for a wire fault as in scraped / grounding, etc. It may only toss the code for the one that gives it a bad signal first.

Just a heads up. Check that top engine wiring close.... and maybe check for vacume leaks.