Honda Tech Tip: Rough Idle and/or DTCs P0171, P0174 or P1171

Honda Tech Tip: Rough Idle and/or DTCs P0171, P0174 or P1171

Select Honda vehicles may experience intermittent rough idle and/or the MIL is on with DTC P0171 (Fuel Trim System Lean Bank 1), P0174 (Fuel Trim System Lean Bank 2) or P1171 (Fuel Trim System Lean During Acceleration). If normal troubleshooting procedures haven’t resolved the problem, it may be caused by a cracked intake manifold gasket(s).

Applies to: All 1998-’99 Passports; 2000 Passport – From VIN 4S6..58W..Y4400001 through VIN 4S6..58W..Y4407271.

The above vehicles may experience intermittent rough idle and/or the MIL is on with DTC P0171 (Fuel Trim System Lean Bank 1), P0174 (Fuel Trim System Lean Bank 2) or P1171 (Fuel Trim System Lean During Acceleration). If normal troubleshooting procedures haven’t resolved the problem, it may be caused by a cracked intake manifold gasket(s).

If this is the case, replace both intake manifold gaskets (P/N 8-97237-538-0).

REPAIR PROCEDURE:
Refer to page 6A-22 of the 1998, 1999 or 2000 Passport Service Manual.
1. Remove the intake manifold from the cylinder heads. Separating the upper and lower intake manifold sections is not necessary.
2. Remove both old intake manifold gaskets. Be sure to carefully remove all of the old gasket material.
3. Install the new intake manifold gaskets.
4. Reinstall the intake manifold with the new EGR valve gasket (P/N 8-97104-317-1) and the new throttle body gasket (1998-’99 models: P/N 8-94389-939-0; 2000 models: P/N 8-97193-729-1).

Technical service bulletin courtesy of Honda Parts Express.

You May Also Like

Toyota Prius Battery Codes P0A7F, P2011 and P0A80

A second generation Toyota Prius is at least 12 years old and batteries may need to be replaced. Here’s what the codes mean.

Battery pack replacement is becoming more common as hybrid vehicles age. The second-generation Prius started with the 2004 model year and lasted until 2009. They have racked up many miles in the past decade or more, and the nickel-metal hydride battery is probably not providing the same range as before.

Air Ride Diagnostics: Reservoirs and Compressors

The secret to diagnosing air ride problems is knowing what criteria the system uses to regulate the compressor/reservoir and having the right tool.

Mazda SkyActiv Engine Service Tips

These engines have been reliable, but there are four pattern failures you might see.

Honda Indirect TPMS Systems

Honda indirect TPMS systems do not have air pressure sensors inside the tires.

Honda Oil System Inspection

The leading cause of low oil pressure-related complaints with Honda vehicles is the oil level.

Other Posts

Now Available – March’s Digital Edition of ShopOwner

The March issue includes technical and management content and is free to download.

ADAS Calibration Tips

Here are 10 tips to follow during ADAS Calibration.

ADAS Calibration Aborts

Knowing the common “hiccups” can save you time and money.

Fuel Pumps and Cranking

Diagnosing the problem comes down to understanding what causes a loss of fuel pressure.