03RCSB

iTrader: (2)

Alright guys, I have an 03 RCSB with the 5.3l in it. Two days ago while taking an onramp to a highway the check engine light starts flashing. Pull the code its and engine misfire code. Now today it happened again and the truck has no power at all. Pulled the code and it was po101, the MAF code.

The truck hesitates, doesnt shift right, it also idles low at around 400-500rpm. I checked the MAF and its getting reference voltage, I cleaned it as suggested in another thread, its the stock airbox so I didnt over oil a filter element. I dont know what else to look at.

If anyone can help me out id really appreciate it, dont want to take this to a shop and get charged out the ***.

Thanks

One_Slow4.8

do you think you could have possibly got a batch of bad gas? is it causeing knock?

Nick™

iTrader: (2)

mileage? it might just be time for some new plugs and wires.

03RCSB

iTrader: (2)

only 54,000 miles.....I heard the bad gas thing a few times.....and it actually does sound like a knock if I get on it real hard......I actually just had filled up, its almost at half a tank now...think putting 93 in it will change anything?

dc_justin

iTrader: (13)

P0101 is a code relating to the calculated airflow (from VE) is too far out of range from the measured airflow (MAF). On a stock truck with no previous history of this problem, this signifies to me that you have developed a substational intake or vacuum leak at some point after the MAF sensor.

Check your intake tubing first, then all vacuum lines (back of the intake as well), then intake manifold gaskets.

03RCSB

iTrader: (2)

dc justin, that code was thrown once....the rest of the codes were the misfire, I had checked all of the intake tubing and also the vaccuum lines, I have a mechanic buddy that helped me check....do you think it could be bad gas...this was also shortly after I filled up and nothing like this has ever happened before

dc_justin

iTrader: (13)

I don't think that the two problems are independent. For that code to have thrown, at some point there had to be a difference in measurement vs calculation. If there is a significant leak, you'll be running very lean and that can trigger your misfire problem.

Bad gas won't explain the P0101...

03RCSB

iTrader: (2)

Alright I guess ill head back out some time tomorrow and check all the intake tubing and all the vaacuum tubing again, kinda sucks tho cuz its my daily

03RCSB

iTrader: (2)

One more bit of info, the misfire problem only happens under load, if I drive around town and stay inder 3000rpm, I dont get any misfire codes, but once I head uphill or put some pressure on the engine, the code gets thrown I have not seen the po101 code again but the misfire happens alot.

Holty

iTrader: (6)

Just throwing this out there but could possibly be a clogged cat although not likely at that milaeage and would not also cause a maf code.