Expert advice needed: P0131 and P0137 on 02 Olds

[Ryan]

I have an 02 Olds Intrigue with the 3.5 v6. Today the check engine light came on. On the way back home, I stopped at Auto Zone and they pulled code P0131 and P0137. These are codes for the front and rear O2 sensors. Symptoms for these codes include: defective sensor, vacuum leak, engine running lean, or low fuel pressure. The lady at the desk tried to sell me both sensors. My thing is, both of these codes popped up at the same time. What are the odds of both sensors being bad at the exact same time? Rather, I would rather believe they are both telling me the car is running lean. I do not see any vacuum leaks, the engine does not idle fast, and the car runs fine. Any suggestions? I'd hate to replace both sensors to find out that it is still telling me the car is running lean. The fuel filter has been changed within 30k miles. The car has about 95,000 miles on it. I changed thePCV valve maybe 6 months ago. I am waiting till 100,000 miles to change the plugs. I doubt it would be bad plugs because if they were bad it would cause it to run rich not lean right? Help me out. Thanks.

Ryan

 

[Billbert]

Are you running Top Tier gas? If not try adding a good FI cleaner (Techron or Regane) and see what happens. Also might want to clean your Mass airflow sensor.

 

[Ryan]

Just running cheap 87 gas. I can try a FI cleaner. Also, in regards to cleaning the MAF, how do I do that safely without damaging the sensor? What should I use? Thanks!

 

[Ryan]

I just read up on what "Top Tier" gas is. I saw that Shell is on the list. I usually go to the Shell gas station by the house to fill up, so I guess I am using Top Tier.

 

[beast3300]

maf cleaner

This stuff works well.

 

[motorguy222]

You could have a bad fuel pump/regulator or fuel filter,this could cause a low pressure that could set the code(s) you are seeing.

Have you checked the wiring under the car to the O2 sensors? They can sometimes come into contact with the exhaust and cause problems.

When was the last tune-up? The car may need one.

These are things that you need to check,he codes listed are the things effected,it doesnt always mean that they are the things that are bad,something that is associated with these parts can make these codes show up.

 

[Ryan]

Here is something for you. After my first 2 replies I left to Wal Mart and the dog gone light turned off. It was probably on for I would guess a total of 10 miles. It hasn't come on since, but I got the fuel injection cleaner and I will clean the MAF anyways. I am sure the light will come back on soon. I just blew 170 bucks on this car back in October to fix an air injection problem and now this problem!

 

[Trav]

Quote:
I just blew 170 bucks on this car back in October to fix an air injection problem and now this problem!


I think the answer maybe in this system.There maybe to much air getting into the exhaust stream,basically duplicating the same condition as a vacuum leak for the O2 sensors but without any actual vacuum leak in the engine.I seriously doubt both sensors went bad at the same time.

 

[mechtech2]

You are right about both sensors going bad at the same time.
It would be a huge coincidence.
But like they said and you know, you can have all sorts of problems that would throw these codes.
Vacuum leaks, PCV system EVAP system, manifold or intake gaskets, injectors or 'O' rings, MAF sensor, intake or temp sensor...

You see, there are too many things to list and point to.

 

[Ryan]

I checked the vacuum hoses where I put the new check valve on and everything appears to be okay. I had to drive the car about 30 miles round trip tonight and still no engine light. I did pick up some of that CNC MAF cleaner on the way though and will clean the MAF anyways. Its probably a matter of time before it goes off again. I need to just go ahead and get a decent scanner with freeze frame data, but too much dog gone money right now.