Figured I'd separate my questions into two different threads so as to decrease confusion.

Ever since I put on my intake, I've occasionally clear a CEL that comes on infrequently. Often it's a combination of codes P0171, P0174, and P1000. Sometimes they stay off for days, and sometimes they come back in a matter of hours. It's not often all three codes at once; but sometimes.

If it helps, here's what the codes mean:

P0171 System Too Lean (Bank 1)
P0174 System Too Lean (Bank 2)
P1000 Check of all OBDII Systems Not Complete

This light being on wouldn't bother me except that sometimes (like tonight, when it came back on on the way home from my doctor's appointment), it pings like the engine's is full of marbles and runs kinda sluggishly. I've been using 89 octane gas and the pinging is minimal if even noticeable under ordinary circumstances, and the truck normally runs fantastically well and makes good power.

Could my mass air sensor have just gotten some oil from the new filter on it's sensor element or might there be something else going on? I'm not really able right now because of an injury to do any sort of poking and pulling at my engine bay, so I thought i'd ask first. I can't imagine (other than something being up with the mass air sensor) why the engine wouldn't be getting the fuel levels it wants to get.

Any ideas on this one?

 

If there is oil on the maf sensor then it should be cleaned off. The P1000 is not really important. It just means that the readiness tests have not been completed. P0171/P0174 lean banks could be caused by an air leak in the PCV valve hose, check the hose for any cracks, especially where it connects to the T/body intake. Also check to make sure there are no unmetered air leaks in your intake system.

 

p0171/0174 are signals for O2 sensors. When i changed my air filter to a K&N my O2 sensors went out 1 month. I was told that it was just coincidence so maybe yours was also. Has your mpg went down. You will get a noticeable decrease in mpg if it's your O2 sensors. 45 dollars a piece and real easy to change. Good luck and keep udated.

 

I've been reading all over this site about codes and specific code numbers when people are asking for help. Where are you getting these codes from? My truck doesn't appear to have any way of displaying them. I don't have a problem, but I like to be prepared

Steve

 

Steve,
The people who post code numbers have purchased or used a code reader which plugs into the computer via the plug under the dash (next to the hood release latch). Some of us have purchased tuners (Superchips 1714, Diablo Predator, ExCalibrator, etc.) that also have the ability to read codes.

 

Yup. I've been reading and clearing the codes using my dad's Superchips tuner.

Thanks for the advice, guys. I'll go ahead and clean the sensor and check the lines to see if that helps, but I bet it is the 02 sensors because I don't really feel like I'm getting the mileage that I ought to. My driving is about 90% highway and I generally just set the cruise and forget it. I get right around 315/325 a tank (from full to when the fuel light comes on), and it always takes around 22 gallons to fill up from there. I feel like it maybe ought to be doing better than that, but I don't know since I've only had the truck since the middle of March.

 

Haha, I think I maybe figured it out.

Leaving for a doctor's appointment yesterday I get in the truck and turn the key to start it. Engine comes on line and then immediately dies out. Give the key another turn with the same result.

From an experience with another car, I know what this means; so I go in the house and get a screwdriver and open the hood to see the mass air sensor has completely separated from the silicone connector on the intake tube. Reconnect it and pull the connector out some so that the intake's not bound up and trying to pull itself apart every time the engine torques in the mounts; and everything's running like a top again.

I think that might've been the cause of my CEL problems, but we'll wait a few days and see what happens before I start trying to dance a jig.

 

Glad you found the problem.

 

Man, I'd LOVE to get 325 miles per tank of gas! For the last 7 months I average about 265 before the low fuel light comes on. Changed out the crappy slush-o-matic torque converter last week with a Factory Tech unit and it appears that my mileage is improving substantially. I'll find out in my next 2-3 fillups. My current tank will be skewed since I was pulling a trailer for about 70 miles yesterday.

Glad you found the loose MAF sensor.

 

Yeah, I'm glad I figured that out, too. We'll see here in the next few days if the light doesn't come back on, but right now the truck's running like a champ.

I'm gonna continue keeping records of my fillups and mileage and stuff, just for the sake of having something to do. My exhaust ought to be here Tuesday and once I get it put on and give the truck a couple days of driving around for any adjustments the PCM may have to make, I'll start comparing the mileage numbers from the exhaust and intake to the mileage from just the intake; and so on.

I'm a big geek like that.