HELP!!!! I recently purchased a 1995 F150 XLT with a 5.0 302. I am having some issues with with the engine light coming on it bogging down on me after it warms up. It seems to do it at about the same spot every morning on my way to work and then periodically through out the day. If I keep the gas peddle in the same spot it usually works through the bog and comes out with good power. I just changed the air filter, fuel filter, and plugs and wires. My buddy pulled the codes using the jumper wire and pulled a 172 and a 173. He said, after doing some research that it might be my Mass Air Flow Sensor so we unplugged it and it drove like a champ other than idling a little rough. So I replaced the mass air flow sensor today praying that the problem was fixed and it still bogged down on me when i test drove it tonight. I was told it could be a bunch of things like temp sensor in my coolant system, catalytic converter, exhaust temp sensor. I just dropped $115 on the sir flow sensor and really dont want to keep replacing things that dont need to be replaced if i dont have to. I am leaking a little coolant but have not had a chance to see from where. I dont know if anyone else is aware of having the same issues or knowing someone who has but I would really appreciate any help.

 

Any smoke coming out of the tailpipe? When was the last time you did an oil change? Notice any water in the drain pan? I recently had a similar problem and it was the fuel pump. My 1995 F150 4.9 was sputtering and felt like it was going to die any second. Thought it was the plugs..replaced them. Thought it was the fuel filter....replaced that. Noticed that I didn't hear the whine of the fuel pump initiating when turning the key to the 'on' position. Just some ideas.

 

172= hego always shows system lean
173= hego always shows system rich

how many miles? i'm thinking theres more than 1 problem. were those the only codes? did you reboot the computer after you replaced the maf? unhook the battery and turn the headlight switch on for about a half hour and then hook the battery back up and see what you got from there. whats an exhaust temp sensor? never heard of one(at least not on these trucks). you have 1 oxygen sensor right? is there an exhaust leak? does it idle rough? whats the fuel pressure? you could test a few sensors(ect, tps, iat) if you have a voltmeter and ohm meter.

 

That's not a diagnostic step - it's a waste of time.There's not one.Low coolant can cause this since the ECT only reads wet temperature, and it's near the top of the engine. If you don't have time to find the leak & fix it right away, at least keep the coolant topped up. Remember that adding plain water will cause the engine to rust inside, so mix up some coolant & keep it in the truck.

 

Well, i appreciate all the help. I changed out the Mass Air Flow Sensor and it ran better but still bogged and the engine light continued to come on. So I changed the Exhaust O2 Sensor, which I previously refered to as the "exhaust temp sensor" and it runs AWESOME. It is such a relief to have it running good.

One other quick question....I have some of infamous rear fender rust and was wondering if anyone, having the same issue, has purchased yfender cover/dressing and if so what do they recommend.

Thanks again for the help.