I Have A 1997 5.4 Triton In An F-150 ,I HAVE CODES THAT DON'T COME UP IN MY BOOK, Can Anyone Tell Me What They Mean? They Are P1506, Po136,p0156,p1131,p1151,p0171,and P0174.

 

Assuming these are Continuous Memory Codes here's what the Ford TSP Says -
P1506 - IAC Valve Assembly - Check for vacuum leaks, specifically at the EVAP Cannister.
P0136 - Fuel Control - Indicates possible wire / voltage problem or a bad sensor (HO2S)
P0156 - Same result as P0136
P1131 - Fuel Control - Correcting for overly lean condition
P1151 - Same result as P1131 - Fuel system not switching at fuel trim
P0171 - Fuel/Air Ratio is too lean
P0174 - Same result as O171 (too lean)

Here's the reference list from Fords TSP - (Things to check first) as possible causes for your Codes. It's a place to start - hope this helps....

DTCs HO2S Reference list:

-- HO2S-11 = DTCs P0171 and P0172

-- HO2S-21 = DTCs P0174 and P0175

Possible causes:

Fuel system

-- Excessive fuel pressure.

-- Leaking fuel injector(s).

-- Leaking fuel pressure regulator.

-- Low fuel pressure or running out of fuel.

-- Contaminated fuel injector(s).

-- Vapor management valve (VMV) leaking.

Induction system

-- Air leaks after the MAF.

-- Vacuum leaks (vacuum lines and gaskets).

-- Restricted air inlet.

-- PCV system.

-- Fuel purge system.

-- Improperly seated engine oil dipstick.

EGR System

-- leaking gasket.

-- Stuck open EGR valve.

-- Leaking diaphragm.

Base engine

-- Oil overfill.

-- Cam timing.

-- Cylinder compression.

-- Exhaust leaks before or near the HO2S(s).

l Check intake air system for leaks, obstructions and damage.

l Check air cleaner element, air cleaner housing for blockage.

l Verify integrity of the PCV system.

l Check for vacuum leaks.

l Are any of the above concerns present?

Yes
SERVICE as necessary. COMPLETE PCM Reset to clear DTCs. RERUN «Quick Test».

No
GO to «H42».

97 F250LD 4x4 Lariat 5.4 Extended Cab

 

Just a quick thought! This is similar to the errors I was getting on my 97 F150 5.4L. I went the usual route of replacing all 4 O2 sensors and still had the rough idle and error codes.... I finally found a thread on this site to talked about a vacuum leak at the back of the intake. The rubber elbow off the back of the 5.4 intake is very close to the firewall and over time the heat will deteriorate the rubber at the elbow bend. This elbow is part of the PVC assembly coming from the valve cover. I had to use both hands to check the elbow because of the limited clearance. Should enough the elbow basically fell off of the intake nipple. Once I replaced the elbow, no more error codes, idled normal, just out $$ on four O2 sensors that I probably didn't need to replace.

Just a thought you might want to climb up over the engine and check that elbow coming off the back of the intake. If I find the link to the earlier thread I will post it.

Hugger94

 

I also had a similar issue w/ mine and some of the same codes if I recall - it was a hose that had become disconnected at my EVAP Canister. -

 

Follow hugger94's tip and resolve the vacuum leak problem first..

That PCV elbow is the most common source.

Once the leak is fixed, reset the computer and drive it for a few days to what, if any, codes might return.

Steve

 

thanks guys .I FOUND THE BROKEN ELBOW RIGHT WHERE YOU SAID IT WOULD IT WOULD BE . FIXED AND THE TRUCK RUNS PERFECT. THANKS AGAIN