So my ranger has been spiting out these code for a while now. This is the fourth time the P1151 has popped up. On long trips with more than a hour at highway speeds the check engine light comes on and it will give me these codes. I will drive it around town and the light will go off after a few days. It will run rough during the trips when the check engine light comes on at stops and slow speeds. I would turns off the interstate and it would be running super rough, and when I go back to highway speeds it would run fine. If I also turn it off for a few it will then run normal in town. Are there any quick fixes and will I hurt anything for continuing to drive it this way?

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99' 4.0L 4WD XLT with 155K miles

If I'm not mistaken those are O2 sensor codes, had the same exact problem, double check though just to be sure

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2001 Ford Ranger Edge 4x4 V6 3.0l Extended Cab
33x12.50x15 Goodyear Wrangler Tires
15x8 American Racing Outlaw 1 Rims

Sounds like a vacuum leak check your lower injector seals

Ok, so when I drove to work last night in it the check engine light went off. This is like the fifth time it done this, spit out those o2 sensor codes and then the light goes off. So would the vacuum leak be something easy to check? It is my only vehicle so I can't tear it apart too much. Thanks for the help.

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99' 4.0L 4WD XLT with 155K miles

Check to see if the upper intake bolts are tight.

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2000 Ranger Extd Cab XLT, 4X4 Off Road, 4.0L, Auto, 8.8 - 4.10's, 01 grille & lights swap.
69 Mustang, modified 5.0, & 5spd.(project)
99 Explorer Sport, 4.0 SOHC, Auto, 8.8 - 4.10's, PW, PL, PM, Cruise, Tilt. (Wife's DD)
05 F-150 2WD Regular Cab. ( My DD)

I would get a can of carb cleaner and spray it around intake of idle changes you found leak