Engine Codes

bremkat · May 1, 2008

2004 GMC Yukon 4wd 5.3L

I had the check engine light come on and when I check the codes I get 2 code each time. P0101 and P0171. What should I look for or do to resolve these codes?

Josh

minibike132 · May 1, 2008

Check for an intake leak... or any unmonitored air getting into the manifold. Intake leaks are common.

ChevyTech007 · May 1, 2008

As stated above, the intake gaskets are very probable. You might want to check this also.

This message applies to all 1999 through 2004 Chevrolet, GMC, Olds, Buick and Cadillac pick-ups and utilities that are equipped with either the 4.8 liter, 5.3 liter or 6.0 liter Gen 3 V-8 engines. Recent warranty analysis indicates that both the MAF, or mass airflow sensor, and the MAP, or manifold absolute pressure sensor, are being replaced for a MAF sensor code P0101. The cause may actually be a MAP sensor failure causing the MAF sensor code. One of the MAP sensor’s primary functions is the calculation of the speed density formula, which is compared to the MAF sensor reading. Should the MAP sensor fail, the PCM may interpret this as a MAF sensor concern and set a P0101 code. If diagnostics are followed thoroughly the technician may find a MAP sensor failure causing this condition. In conclusion, when a MAF sensor code of P0101 is found the technician needs to verify the proper operation of the MAP sensor before concluding that the MAF sensor requires replacement.

C6Racer · May 1, 2008

Intake leaks are common? Guess I've been lucky. I have 148k miles on my 5.3L and the only codes I've gotten were for both S.A.I. check valves at around 130k miles. My valve cover gaskets seem like they're starting to go. Is there anything else I should "look forward" to replacing?

bremkat · May 4, 2008

I tried cleaner on the MAF. The light is gone and I have had no trouble. In fact it seems to be running a little better since. Thanks for your help. I hope this is the problem and no a leak.

BretD04GMC · July 25, 2008

I just got my second P0101 code since owning my truck. The first time was apparently due to a dirty K&N filter after driving through a very dusty area. Cleaned the filter and the code went away. That was about a year or so ago. Since then, I've also switched the K&N filter on my CAI for an AEM Dryflow that uses no filter oil.

Today, I got the P0101 code again. I suspect it may again be due to a dirty air filter. I drive by the beach every day and also work by the beach. The truck gets dirty very quickly every week, so odds are the filter is due to be washed.

95Sierra2500 · July 25, 2008

I just got my second P0101 code since owning my truck. The first time was apparently due to a dirty K&N filter after driving through a very dusty area. Cleaned the filter and the code went away. That was about a year or so ago. Since then, I've also switched the K&N filter on my CAI for an AEM Dryflow that uses no filter oil.

Today, I got the P0101 code again. I suspect it may again be due to a dirty air filter. I drive by the beach every day and also work by the beach. The truck gets dirty very quickly every week, so odds are the filter is due to be washed.

A properly cleaned and oiled K&N won't cause any issues with your MAF. I've got a K&N on 3 different vehicles, and NONE of them have given me issues with the MAF sensor. Whenever I purchase a K&N, the first thing I do is wrap it in rags and let it sit for a day to soak off excess oil. I then run it for about a year. I clean them about once a year, and always clean from the clean side to the dirty side using the spray-on cleaner. Let dry, then use the aeresol oil, not the squeeze bottle. I've never had an issue with an over-oiled K&N using the aresol. In fact, every over-oiled K&N I've ever seen was recharged using the squeeze bottle...coincidence? I think not.

BretD04GMC · July 25, 2008

A properly cleaned and oiled K&N won't cause any issues with your MAF. I've got a K&N on 3 different vehicles, and NONE of them have given me issues with the MAF sensor. Whenever I purchase a K&N, the first thing I do is wrap it in rags and let it sit for a day to soak off excess oil. I then run it for about a year. I clean them about once a year, and always clean from the clean side to the dirty side using the spray-on cleaner. Let dry, then use the aeresol oil, not the squeeze bottle. I've never had an issue with an over-oiled K&N using the aresol. In fact, every over-oiled K&N I've ever seen was recharged using the squeeze bottle...coincidence? I think not.

I too have never had any trouble with oil from a K&N. My DTC seems to be just from the filter(s) getting too dirty (from the conditions I drive in) and restricting some of the air flow. I changed to the AEM only because I liked the idea of not having to oil the filter and therefore reducing down time during cleaning.

Checking the AEM Web site, they recommend cleaning their filters more often. In fact, every 3,000 to 5,000 miles if you drive in dirty conditions.

A little Simple Green soaking tonight should hopefully clear up my P0101 code.

On a side note: Gotta love having a ScanGauge II on the truck. As soon as I saw the MIL was on I was able to instantly pull up the code to confirm the problem.