Quote:
|
I also got code 174 (engine bank lean)
|
The fact your air bridge came off that is almost certainly the cause of your lean code. However, this is as good a place as any for the following:
Stuff that will cause your car to throw lean codes:
Section 1: LTerms are High On One Side Only
1) Vacuum leak: If your LTerms only go high when the car is at little to no throttle, then the chances are 99.999999% that you have a vacuum leak.
2) Exhaust leak: Typically, this will only cause one side to throw a lean code. If both sides are throwing a lean code, then you should start looking at the items on your car that control the overall fueling.
3) Bad O2 sensor: A dirty or 'blind' O2 sensor (from running leaded gas etc...) will percieve a lean condition.
4) O2 Connection: Improper power to the O2 sensor (ground or whatever) will percieve a lean condition.
5) Cutout too close to O2 sensor, or open headers: The reversion in the exhaust system exposes the O2 sensor to too much oxygen causing a lean condition to be seen.
6) Bad Injector: A faulty injector will cause the LTerms on one bank to go high. The lean condition will be intermittent and LTerms will typically be higher at lower throttle conditions.
7) Misfire, One Bank: The unburned oxygen leaving the bad cylinder causes the O2 sensor to percieve a lean condition.
8) Coolant In Combustion: If you have coolant exiting the cylinder it will cause the O2 sensor on that bank to percieve a lean condition.
9) Long Tubes: Cold conditions in combination with some long tube headers excessively cool the oxygen sensors. If the oxygen sensor cannot get up to operating temperature it will falsly report a/f to the lean side. This is typically seen during the winter at low RPM freeway driving.
Section 2: Both Banks Showing Lean - LTerms High on Both Sides
1) MAF: If your MAF is not clean or is not reporting a/f properly it will upset fueling on the lean side causing both banks to throw a lean code.
2) Fuel Pressure: If your fuel pressure is too low for your current program (plugged filter etc...) fueling will be inadequate for all operating ranges and your vehicle will run lean.
3) Big Cam: Exceptionally large cams will generate too much reversion in the exhaust (and intake) causing the fueling to be upset by both the MAF and the O2 sensors at lower RPMs
4) Big Exhaust - Long Tubes: If your exhaust is too large, or moves the O2 sensor too far away from the engine, the O2 sensors cannot get up to operating temperature and will falsely report the a/f ratio lean.
Vacuum Leak: A large vacuum leak will cause the motor to run lean on both banks.
Leaded Gas: Running leaded gas destroys the O2 sensors with a couple miles. The lead plugs the oxygens sensors making them percieve a lean condition.
Multiple Misfires (Both Banks): The excess, uncombusted air leaving the cylinders causes the O2 sensors to percieve a lean condition.
Poor Tune: A poor tune made to the MAF table, Injector Flow Rate Table, Injector Offset table, can cause your car to run lean.
Rail Voltage or Wrong Injectors: If your car is having voltage problem, the inadequate power causes the injectors to fuel improperly and late causing a lean condition and poor running.
I reattached it, tightened it and drove it. I still heard the same puttering, but not nearly as bad.
Please let me know how it turns out. I also have the Random Tech setup, but I have TPIS headers.
Linear Mode
