2003 truck 4.2 engine 177K miles
Truck is running rough,I can hear it missing at the tail pipe, I pulled off each spark plug wire, one at a time. Each time the engine ran worse. I checked for intake/vacuum leaks by spraying ether all over the top of the engine,no change in idle.

The EBD II code reader gives
P1000 checks not complete, more driving required so I drove it 114 miles
P0721 output shaft speed sensor circuit range perfomance
P1131 lack of HO2SII switch sens indicates lean
P0171 system lean bank 1
P0316 misfire start up
P0302 cylinder 2 misfire
P0306 cylinder 6 misfire
What does this mean?
thanks

 

Plugs...

 

Yep replace them all

 

With motorcraft

 

My post is results after putting new plugs in yesterday
What is the P1131?

 

lean condition on bank 1. probably either fuel injector(s) or vacuum leak

 

I agree that I'd start with the plugs. On my '99 4.2l, I had trouble with a number of codes, including P01131 and P0171. In the end, I had two problems: 1) the infamous pcv system rubber elbow under the throttle body, 2) upstream 02 sensors. The elbow is easy to get at and replace. The 02 sensors can be a royal pain in the butt because if they're original, they're pretty much 'welded in' by time. They had to be fired up orange hot to get them out. Good luck with it. Hope changing plugs will do the trick.

 

What plugs did you use? P1131 is a lot of times a slow O2 sensor, upstream bank 1.

 

After plugs, this is the only remaining code?

 

Thank you for the responses. I will try to answer them all in one post.
2003 truck 4.2 engine 177K miles

I put in new plugs yesterday and drove the truck less than 200 miles to rescue a friend who was broke down on the Interstate.
The plugs are Motorcraft SP-504 AGSF34FM gapped at .045

Truck is running rough,I can hear it missing at the tail pipe,
I pulled off each spark plug wire, one at a time. Each time the engine ran worse.
I checked for intake/vacuum leaks by spraying ether all over the top of the engine,no change in idle.

The EBD II code reader gives
P1000 checks not complete, more driving required so I drove it 114 miles, plus more
P0721 output shaft speed sensor circuit range performance
P1131 lack of HO2SII switch sens indicates lean
P0171 system lean bank 1
P0316 misfire start up
P0302 cylinder 2 misfire
P0306 cylinder 6 misfire

I think that answers all responses.
How do I test fuel injectors and where is the O2 sensor? Should I heat it with the acetylene torch to get it loose?