O2Form

Here is my opinion, sounds like you have dirty injectors. Could be from the fuel lines and the fuel rail starting to rust. It is a comon problem on returnless fuel system. You can pull the injectors and fuel rail easily and inspect the screens in the injectors for dirt-rust.

My TA was so badly rusted it finally started to miss fire, all the injectors were paratially blocked and the fuel lines and fuek rail were ruined. GM has a bulletin out on it someplace, but most dealers will deny it.

On mine i just removed the pulsator on the fuel rail and you could see rust and flakes.

1FSTLS1

iTrader: (9)

Well I took out all the injectors this am and dont see anythign obvious so I will try to clean them off and sparay them witht he air compresser and put the 4 from the drives side back in the passenger side and see if my problem goes from p0171 (bank 1) to (bank2) p0174.

O2Form

Fantastic but it still doesn't mean they are clean and flowing properly. Go get a large bottle of Chevron Techron, I thinks its 20ozs....then add that and fill it up with gas. Its dam good fuel injection cleaner, in fact its what the dealers have. Then see what happens.

I use a product from Lucas called fuel system treatment in ever tank full to be sure the injectors stay clean. I add a few ozs every fill.

O2Form

If it stays on that side you may have a small vacuum leak on the intake.

O2Form

How did plugs look? Any look different than the others? sometimes that will show you which cylinder is lean. Another test i've done is hold the engine steady at 1500-2k rpm then pull each injector plug off one at a time and watch the tach. See if they all drop the same amount.

1FSTLS1

iTrader: (9)

Yea I was definatly wondering about that.

wssix99

iTrader: (5)

Just switch your left/right injectors and see if the problem switches sides.

2001WS6Vert

If the car runs O.K. it's not injectors. Alldata and a Tech II and it's an easy diagnosis. Too bad your not near Cincy, I'd charge you an hour labor at my shop and it would be done. A local shop or dealer probably won't charge you much to diagnose this problem vs all the time and money consuming guesswork.

1FSTLS1

iTrader: (9)

Yea well I dont know any one local or do I trust any one.

2001WS6Vert

It's just that it's laughable that this is such a long post about what is a simple thing to diagnose. So many uninformed helpers that send you barking up the wrong tree. I would bet a dealer would be a rather inexpensive fix and you would be done with this and move on to other problems in life. I've dealt with many people over the years that spend a lot of time and money trying to solve a problem that a competent and trustworthy shop can diagnose quickly and inexpensively. If you give me a fax number I will send you the Alldata flow chart for this code. It is written specifically for a Tech II but can usually be ran through with a generic scanner. If you don't have a way to read data I guess you can keep throwing parts at it.

COSTIGAN86

iTrader: (8)

Agreed. I work at a dealer and you wouldn't believe how many people come in with a problem and have thrown $1000 worth of parts on it. Yes, the dealer usually charges more per hour to fix, but it will get fixed. You spent more on parts you didn't need than the extra labor charges.

COSTIGAN86

iTrader: (8)

Have you tried spraying carb clean around the intake? Do this with it running and the rpms will go up if there is a leak.

2001WS6Vert

I'm an ASE master tech, also L1 advanced engine performance certified. Ohio E-check certified. Owned my own shop 23+ years, own 5 scan tools, subscribe to Alldata & the International Automotive Technicians Network. I know I'm bragging but also showing I'm old. $100 says I can solve it in 1 hour. Oh, and I spray carb. cleaner too.

2001WS6Vert

This post was started Sept. 19th. I did give advice in post #6 and also offered to fax him a flow chart for code 171 in a later post. If you know anything about cars and read through some of the suggestions (like swapping injectors) it's pretty pitiful. I keep getting e-mails from this thread because this "mystery" problem can't be solved. Any decent driveability tech would have a quick answer for this 99% of the time. Unless the OP has access to a scanner and knows what he's looking at I would say at this point he would be better off taking it to a shop. About dealers, most mechanics want to eventually work their way up to being a dealership line mechanic. It is generally where they find the best pay and benefits so the dealerships for the most part have some of the best techs. It is hard for an independent garage to retain good techs unless they don't like dealerships (usually because of the internal politics). I do the driveability at my shop because a skilled driveability tech is too expensive. Thanks for the lesson about the usage of carb. cleaner, I don't know how I've lived this long.

Raist103

iTrader: (12)

didnt read the entire thread but i had the same issue when i got my car. changed all 02s and made no change. found the hose from lid to tb had a hole changed that and it went away for a while. then changed maf and all has been well since.

1FSTLS1

iTrader: (9)

Part of the problem is I have not put out the time and effort to fix this I have other things I have been messing with. After I put the injectors back in I will mess with it. I need to try to get a scanner soon. Is this what you show in alldata if not I will need to get my faxmacine hooked up to the phone line and take you up on the offer. thanks all.



CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during open and closed loop. During Open Loop the PCM determines fuel delivery based on sensor signals, without oxygen sensor input. During Closed Loop, the oxygen sensor inputs are added and used by the PCM to calculate short and long term fuel trim (fuel delivery adjustments). If the oxygen sensors indicate a lean condition, fuel trim values will be above percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0 percent . Short Term fuel trim values change rapidly in response to the Heated Oxygen Sensor (HO2S) voltage signals. Long Term fuel trim makes coarse adjustments in order to maintain Air/Fuel Ratio of 14.7:1. If the PCM detects an excessively lean condition, this Diagnostic Trouble Code (DTC) will set.

CONDITIONS FOR RUNNING THE DTC

DTCs P0101, P0103, P0108, P0135, P0137, P0141, P0200, P0300, P0410, P0420, P0430, P0440, P0442, P0443, P0446, P0449, P0506, P0507 or P1441 are not set.
The Engine Coolant Temperature (ECT) is between 75-115°C (167-239°F) .
The Intake Air Temperature (IAT) is between -20 to +90°C (4-194°F) .
The Manifold Absolute Pressure (MAP) is between 26-90 kPa (3.7-13 psi) .
The vehicle speed is less than 137 km/h (85 mph) .
The engine speed is between 400-3,000 RPM .
The Barometric Pressure (BARO) is more than 74 kPa (10.7 psi) .
The Mass Airflow (MAF) is between 5-90 grams per second .
The fuel level is more than 10 percent .
The Throttle Position (TP) is less than 90 percent .
CONDITIONS FOR SETTING THE DTC

The average long term fuel trim cell value is above 23 percent .
All of the above conditions are present for 6 seconds .
ACTION TAKEN WHEN THE DTC SETS

The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC

The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Use a scan tool in order to clear the MIL and the DTC.
DIAGNOSTIC AIDS

The system will go lean if an injector is not suppling enough fuel.
A lean condition could be present during high fuel demand.
Using scan tool, review Failure Records. If an intermittent condition is suspected, Refer to Intermittent Conditions. See: Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions
TEST DESCRIPTION

Steps 1-6
Steps 7-8
The numbers below refer to the step numbers on the diagnostic table.

If conditions were not corrected, refer to Fuel System Diagnostics for a possible fuel problem. See: Component Tests and General Diagnostics\Fuel System Diagnosis
If conditions were not corrected, a worn cam, worn intake or exhaust valves, or other engine mechanical failures may be at fault.

2001WS6Vert

It looks like you have part of it. I don't see the actual tests. It says steps 1-6 and 7-8 but I don't see them.

1FSTLS1

iTrader: (9)

Welll I took the entire fuel rail off and cleaned it out took the pressure regulator out cleaned every thing. I cleaned all the injectors by sending 12v to them and running cleaner through them. Got it back togather and ran the crap out of it for maybe 5 miles and no light yet. I will give it more time to see if the problem comes back or moved to the passenger side.

COSTIGAN86

iTrader: (8)

So all your GM dealership experience and YOU can't do routine maintenance? A simple fuel volume test would have pinpointed this. Guess I'm lucky to be alive, seeing how that flying screwdriver I had on the alternator sparked and lit the carb clean I sprayed on the intake...

COSTIGAN86

iTrader: (8)

Routine maintenance is that area in the back of your owners manual where it tells you which items to replace at which mileage/date intervals. Guess they didn't teach you how to read in internet mechanic school.