Trying to get my son's truck to pass emissions in NH, the shop (and I) read codes. The ruck is a 96 with a 4liter standard transmission
P0155 (O2 sensor heater circuit (bank 2 sensor 1)
P0401 (EGR flow insufficient detected)
P1151 (No description available) though with my tester its asking if this is Ford or Mazda

Here are some of my questions:
Which O2 sensor is bank 2 sensor 1? I am thinking its the driver side sensor.

I changed out the EGR valve about 50K miles ago, could it be bad again or could it be something else... OR could the O2 sensor cause other issues...

I have until Tuesday the 26th to get it reinspected..

Thanks
Royce

 

you are correct Bank 2 is the drivers side. sensor 1 is the precat sensor. the p0155 is for the heater circuit in the bank 2 sensor 1, O2 senosr.

1)I would replace the O2 sensor

2) the p0401 is most likely caused from a faulty DPFE sensor......I would check the hoses to the dpfe sensor for damage and if they are ok, replace the sensor.

 

p1151 relates to the bank 2 sensor 1.

 

Thanks for the help so far, I replaced the O2 sensor and the DPFE sensor and eliminated the 1st two codes, Now it still has the P1151 which says:

Ford: Lack of H02521 Switches-Sensor indicates lean.


I erased the code and will see if it stays off, if it does not, what should I be looking at?

Thanks again
Royce

 

Did you clear the codes with a scanner/reader? Let us know if the CEL comes back. My guess is you will be all set

 

If the p1151 comes back I would change the fuel filter and then do a series of fuel pressure tests. The fuel filter should be changed regularly anyways

 

Thanks for the additional advice. I changed the fuel filter last week at the suggestion of the garage that did the emissions testing and used my scan tool to erase the code. I'll have my son drive it over the next couple of days to see how it goes and then take in for retesting on Monday/Tuesday. I'll update then.

Thanks
Royce

 

Yeah SHOULD. The GM stuff I work on don't have them anymore they are in the tank, so when your fuel pump goes it gets replaced dumb huh?

 

I fought a P0401 code for MONTHS before stumbling across this site. First off, I know enough to get myself in trouble so, all the info I gathered here was a REAL LIFE SAVER.

I spoke with a couple local "mechanics" and all they wanted to do was keep throwing parts at it and HOPE to get it right -- WRONG approach.

Listen to what the guys here have to say -- THEY KNOW THEIR STUFF AND I FOR ONE AM VERY GREATFUL FOR ALL THE HELP. THANK YOU.

First I was told it was the EGR, changed it - code came back within 10 miles.
Next I was told try the EGR sensor, again code came back within 10 miles.
Then, it HAS to be the throttle body is clogged up. OK, took it off and cleaned all the carbon out. Although this surely didn't HURT anything, it didn't solve the code problem either, came back AGAIN!

FINALLY, I found this site and started to read the threads.

Took the chance and changed the DPFE, it was the original Ford metal version that they all spoke of getting corroded.

Bought a new plastic one from RockAuto.com for $38.00 and BINGO -- NO CODE and I HAVE A MA INSPECTION STICKER!

It's a 1997 Ford E150 Hightop conversion van with 5.4 L and 160,000 miles and runs like a dream. The fuel mileage seems to have gotten better but I've only put enough miles on it to get all the "monitors" to a ready state so time will tell.

Bottom line, YOU GUYS HAVE HELPED MORE THAN YOU KNOW AND I FOR ONE APPRECIATE ALL THE HELP. KEEP UP THE GOOD WORK!