Greetings all,

I need help once again. After taking the truck off-raoding and getting her a little muddy, it's been running a little rough. Under wide open throttle, it seems sluggish and even to the point of hesitating and picking upspeed very, very slowly. I can see the RPMs going but the car picks up speed very slowly, almost not responding to the command of the gas pedal being kicked down.

I did some normal maintenance,changed oil /filter and air filter and I noticed that the air filter was very filthy and seemed like it had sucked in a small amount of water and mud. I checked the MAF sensor and it looked fine to me but I could also see a trace ofdried dirt in the air intake hose, near the sensor, not much at all..

About a day ago, the Check Engine Light came on and got codes P0172 System Too Rich (Bank 1) and P0175 System Too Rich (Bank 2).

Anybody know what I might be facing here?

Thanks in advance!

 

How many miles on your truck, when was it last tuned? What octane gas are you running?
Mike

 

Hi Mike,

The truck has about 58K miles on it, always use 91 octane andabout 6 weeks agochanged the plugwires to 8mm Magnacore and Bosch Plugs, the one you recommended, don't know right of the top of my head what the part numbers are, but I ordered all parts from the company in Utah (I think...).

 

Are you running a K&N air filter?
MIke

 

No K&N Filter but as mentioned, there was some mud residue in the air filterhousing and the air intake tube where the sensor is located. Looking at the sensor however, it doesn'tseem to be dirty.

 

Good, don't try an clean the MAF with any chemicals, you could kill it.
I have to think on this one, I am stumped.
Mike

 

Well, it looks like it's getting worse. Now the truck sounds like a washing machine. At idle, the truck has this low, repeating humming like a washing machine in it's washing cycle. It seems like it's also running a little rougher now.

Anybody have any ideas at all?

 

Why don't you send me your tele number and a good time to call and we can talk about it more.
Mike
mikeljacobs@comcast.net

 

Couple of causes for the this if you have no oxygen sensor fault codes.

Air leak near the MAFS
Air leak near the IACV
Air leak near the throttle body
Air leak in the inletmanifold gasket or seals
Porous inlet manifold casting
Air leak around injectors
Air leak in injector
MAFS sensor is functioning but inaccurate

 

I had also experienced this problem a couple of times with my Saturn oxygen sensor...Basically this means that an oxygen sensor in bank 1 detected a rich condition (too little oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. This DTC is very similar to P0175, and in fact your vehicle may show both codes at the same time... Common symptom is a drivability problems, although there may be symptoms such as a misfire. Some causes are MAF (Mass Air Flow) Sensor is dirty or faulty. "Note: The use of "oiled" air filters (K&N, etc.) can cause the MAF to become dirty if the filter is over-oiled", a vacuum leak and a fuel pressure or delivery problem... Here are some possible solution with your problem:
[ul][*]Inspect all vacuum and PCV hoses, replace if necessary[*]Cleanthe MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling[*]Inspect fuel lines for cracks, leaks, or pinches[*]Check the fuel pressure at the fuel rail[*]Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.[*]Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)[/ul]Hope this helps... Good luck!!!