So... I have had an intermitten problem with my idle for about 4-5 months now. I idle problem start around october or november when my front o2 sensor went bad. I was having a really bad chuging during idle and when I went to take off I had to baby the gas to get any power at all, if I pressed the gas too much it would just sit there and not do anything. I replaced the o2 sensor and this problme cleared up, but I was left with another problem. My car seems to want to die every 10-15 seconds maybe. It idles around 800rpms consitantly but every so often the idles will drop down to about 500 or 600 for a second and almost die, and then jump back up to about 1200 or 1300. It's never actually died and when I take off of drive its fine. I have been throwing a code lately, I believe its the P0700 that might not be the right code but the code description in auto tap says fuel system too lean. I am pretty sure that I dont have a vacuum leak, one because my vacuum gauge is exactly as it has been for the past 3 years, and two because I have sprayed all over the vacuum lines with carb cleaner and havnt gotten any idle surge at all. I've tried the ground wire upgrade, the extra + from the alt to the fuse box, replaced the fuel filter used injector cleaner several times and I just cant seem to figure out what the deal is. When the code comes on its only on for a little bit, maybe two separate drive sessions and then it goes off again, thats why it frustrates me so much. Any ideas would be much appreciated. I had a friend suggest the fuel pump relay and the fuel pump spd cont relat in the engine fuse box as possible problem causers and am replacing both of those tonight. Let me know what you think guys, I am at a loss

P0700-Transmission Control System Malfunction

Is that the code you're throwing???

no, that must not be the code number then, I will scan it when I leave work and get back on when I get to class and repost the exact code that it is throwing, but the description is correct, I remember it said fuel system too lean

Clogged injectors?

ok, the code is P0171 Fuel system too lean, I changed the relays tonight, didnt help at all, I dont believe its the injectors because I havnt noticed any other syptoms durint regular driving, no bogging during starts or anything like that

If anyone is handy with a autotap I can give you scans to look at?

Maybe the IAC motor? Or maybe the O2 sensor you replaced is defective and is giving the computer inaccurate info and thus the PCM isn't delivering enough fuel.

IAC motor? I havnt ever heard of this... where is it located, also, I dont think it is the o2 sensor, but I will try replacing it, its only like $12

You can test the O2 sensor with a multi meter and a propane torch. Do a google for O2 sensor testing.

I'm still leaning on dirty injectors.

LOL, I knew you wouldnt let me get outta this without pulling those out, I'm gonna take a look at testing the o2 sensor and if that turns out ok I guesssssss I will pull the injectors and take a look at them :rolleyes:

Edit: I think I might try this first

Causes= code P0171 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters (K&N, etc.) can cause the MAF to become dirty if the filter is over-oiled
There could be a vacuum leak downstream of the MAF sensor.


Possible SolutionsPossible solutions include:

In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace if necessary
Check for a dirty fuel filter and proper fuel pressure

anyone have any tips for cleaning the maf and wanna tell me exactly where its located to make sure I thinking of the right thing?

Check out this thread..... I'd also suspect your EGR valve.

http://www.grandprix.net/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004585;p=1&r=nfx

Follow clint's link to that thread, and go down to his post with the diagram and find MAF.


Can you post or email a scan?
(with O2's, long and short term fuel trims (ltft & stft), injector pulse width, and the rpm stuff.. more the better)

The MAF idea sounds good. I would also think of fuel pump resistor or the pump itself.

$12 O2 sensor ?!?!!

Ok, I think I may try and replace the PCV valve and clean the EGR valve tonight, along with the MAF sensor. What exactly do I clean on the EGR, I'm assuming I need to unscrew it and pull it out to be cleaned?

Also, I will post scans tonight

Ok, got scans sooner than I thought I would...

During Idle

RPM 830
STFT O2 bank one sensor 1 10.9%
STFT O2 bank one sensor 2 99.2%
LTFT bank 1 16.4%
STFT bank 1 10.9%
Throttle Position Angle 0.4%
Ignition Timing Advance 27deg
IAC Motor Position 55counts
Injector Pulse Width #1 2.12ms
Linear EGR closed position 1 volts
Mass Air Flow Rate 0.61 lb/min


During Surge at idle


RPM 1022
STFT O2 bank one sensor 1 9.4%
STFT O2 bank one sensor 2 99.2%
LTFT bank 1 16.4%
STFT bank 1 9.4%
Throttle Position Angle 0.4%
Ignition Timing Advance 27deg
IAC Motor Position 68counts
Injector Pulse Width #1 2.48ms
Linear EGR closed position 1 volts
Mass Air Flow Rate 0.585 lb/min


During Cruising


RPM 3964
STFT O2 bank one sensor 1 0.0%
STFT O2 bank one sensor 2 99.2%
LTFT bank 1 -2.3%
STFT bank 1 0.0%
Throttle Position Angle 61.2%
Ignition Timing Advance 15deg
IAC Motor Position 141counts
Injector Pulse Width #1 18.01ms
Linear EGR closed position 1 volts
Mass Air Flow Rate 25.635 lb/min

Do you guys want to see more of the scans or want to see something else?

That ain't cruising, that's floored!