Hi All,

I am new to this board. Like most everyone else the first post comes with a question.

To the point: What does OBD Code P1151 translate to? My 97 F150 4.2l Auto w/ 50K mi. is running terribly. The check engine light is on. I read OBD codes P0153 & P1151 w/ an Actron code scanner. The Actron manual states P0153 = O2 Sensor Circuit Slow Response (Bank 2 - Sensor 1). It states that if the first number is 0, it is a generic OBD code and all are listed in manual. If the first number is 1, it is manufacturer specific, and doesn't list them. I found a site www.batauto.com that listed P1151 = Lack Of HO2S21 Switch - Sensor Indicates Lean. I'm assuming this means H-heated O2-oxygen S-sensor 2-bank2 1-sensor1, pointing to same sensor as P0153. They didn't specify any manufacturer, though. Is this code common to all manufacturers? Does Bank 2 mean cyl. 4,5,6? Does Sensor 1 mean the one upstream of the converter (first sensor exhaust reaches)?

The first thing I did was to replace plugs and wires. They both needed it, badly. The #1 wire lead was broken off in the coil, and I thought I found my problem. New plugs and wires made no difference, though. So, I picked up the aforementioned scanner and read the codes. Apparently, the trouble seems to be an O2 sensor. Bank 2 Sensor 1 is on the drivers side nearest engine, right. I plan on replacing both left and right sensor #1. Should I replace all four (50,000 mi)? I haven't even checked out the prices on them, yet. I am a second shifter and nothing is open until I'm about ready for bed (will be up late today).

Well, thanks in advance for any help.

-beckerhead

 

OK, I got my O2 sensor. I decided to buy just one, until I'm sure it will cure problem. I didn't get to work on it, yet. I cleared the codes and I drove it to work today. Big mistake. It was running terrible when I got there. On the way home it was down on power so bad, I would have been beat off the line by my grandma with her electric wheelchair. The truck was downshifting to 2nd to stay at 45mph. When I got home (10mi 40-45mph), the manifolds and cats were glowing red! The Check Engine light never came on, though. I leave work at 3am and all I want to do is get home. I feel bad about driving the poor girl when she is so sick. I won't drive it again, until fixed.

This can't be an O2 sensor problem alone, can it? Shouldn't it be running in open loop? I would expect it to run much better than this if it was running on lookup tables with no feedback from the O2 sensors. I'm no expert, not even close. But, I think I know the basics. There must be another problem, right. Vacuum leak? Hmm. Burnt valve, piston or cracked head? Both manifolds were red, though. Low fuel pressure? Hmm. Crossed ignition wire? Maybe, I'm not perfect. I will check wires, look for vacuum leaks, and run compression test right now.

Seems kind of like the ignition is way retarded. The computer would have to be doing this, though. It has distributerless ignition. About a year ago, the bolt in the front of the crankshaft, that holds the crank pulley/balancer on, broke. The head just fell right off. Crank pulley slid forward about a half inch and trigger misalingment killed motor. Luckily, I was idling in the driveway when it died, but who knows when the bolt snapped. I had to pull the radiator to get a drill in there, but it came out real easy with an "easy-out" (tapered punch-like thing with left spiral). I think if I pull the bolt back out, I can see if the keyways are aligned. I can't imagine I left the key out, but this will be easy to check and will calm my nerves.

Am I missing something, any comments appreciated.

-beckerhead

 

check you catalatic converts sounds like they might be pluged up had that prob. before and had the same cond. glowing exhaust and no power

 

 

i have a 98 f150 w/ 329.000 on it. runs fine in town but on the freeway it feels like a miss fire got a code P1151. any ideas ?

 

Jerry, your missing a lot.
Of knowledge, that is about how these systems work.
Your only looking at single code points of system reaction to a trouble.
1. The cats running red hot was due to gas burning in the cats from misfiring cylinders. The cat temperatures ran well over 900 degrees when Red in color seen in daylight. You should have codes 420 or 421 now and need to replace the rear sensors as well. An expensive lesson.
Likely you now need to replace the cats because they melted and are blocking the exhaust outlet as the reason the motor can't breath and is down on power.
2. Fix the code issues first before replacing the cats or the same result will happen over again. You lost the cats due to the trouble. It was never the cats to begin with.
3. The 153 and 1151 codes point to the same cause.
Likely a vacuum leak into the intake system as excess air that causes the Lean condition the Ox sensor picks up. The Ox sensor is only doing its job.
If you see a code 35x, it is a coil circuit code that will mean no spark, only gas passing through the cylinder to cause the Cat damage.
See what I mean about knowing the bigger picture?
You need to maintain the truck a little better so these things don't stack up and become big problems.
Good luck with it..