New B4000 owner, about to lose it over Check Engine Light

[TheMuffinOfEvil]

I recently got a 98 B4000 4x4 Manual transmission, the check engine light keeps coming on and reading both error codes for Left bank running lean and right bank running lean. I have changed the mass air flow, all three O2 sensors, and run injector cleaner through the motor. I do not seem to be getting the gas mileage I think I should get or I would just ignore the light, can someone give me some advice on what to try next, what could be causing this? Truck is right at 150,000 miles.

 

[Combs Customs]

have you done the easy stuff like check for vacuum leaks?

 

[m8r8j]

u try resetting the ecu?

 

[TheMuffinOfEvil]

The ECU has been reset, and I have tried to check for any leaks, not sure where to check on this truck specifically though other than the break booster and the lines that are plainly visible around the motor.

 

[Toms01PSD]

It's easy...smoke machine to a vacuum line...you'll notice any leaks in a heart beat.

 

[TheMuffinOfEvil]

I am so sorry, I lost the peice of paper its written on and I dont have the code puller handy, its the same two every single time though, Left Bank Running Lean, Right Bank Running Lean.

 

[TheMuffinOfEvil]

When Auto Zone pulled it there reader said Bank 01 and Bank 02 instead of Left and Right like on my own reader, if that makes any difference at all.

 

[m8r8j]

try cleaning the IAC with some MAF cleaner. pull it right out and soak it down.

 

[TheMuffinOfEvil]

What is the IAC? My car knowledge is only slightly above average, I am a quick learner though.

 

[Destroyer000]

definitely sounds like a vac leak.. check the egr tube for cracks an a leaky seal at the intake. this is what was wrong on my buddies 96.. through the same codes. .. also spray some carb cleaner around the intake. if it revs up thats your problem .

 

[Destroyer000]

iac IDLE AIR CONTROL... its a silver can on top of the intake close to the throttle body.

 

[TheMuffinOfEvil]

Thank you guys, I will try that tommarow and see how it goes.

 

[m8r8j]

it allows the right amount of air into the motor during idle, if its not seating properly it could make the engine run too lean. try cleaning it, and then if that doesnt work as a last resort id buy a new one or grab one out of a junkyard. i think their like 40 bucks new maybe? but check for vacuum leaks before you go spending money.

 

[94STXRanger]

Have you checked for correct fuel pressure?

 

[TheMuffinOfEvil]

Is there a proper method for checking for leaks all over? Or do you just follow all the lines along?
I dont know how to check for the correct fuel pressure.