Check engine Light
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Check engine Light
I have a 1988 F150 xlt Lariat w/300i6 and 5 speed. When I am cruising @78mph/2900-3000rpm every once in a while my check engine light will blink twice and stop and then blink twice again. I'm trying to understand why this would be coming on only during that speed/rpm range. Trk has 150,000 miles and I just replaced the (cracked) exhaust manifolds. Also, when accelerating from about 2000rpm, the engine wants to buck or hesitate until I back off the accelerator. Any help would be appreciated.
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Joined: Jul 1999
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Check engine Light
Hdlinerman ,
Sounds like maybe the O2 sensor has gone south ...thats the only time my check engine light has ever gone off , Mine died about 95k miles . Plus where you have just R&R the exhaust manifolds , its possible they got some dirt and or other contaminants on it . Id recheck to make sure you got all the wires connected too .
Sounds like maybe the O2 sensor has gone south ...thats the only time my check engine light has ever gone off , Mine died about 95k miles . Plus where you have just R&R the exhaust manifolds , its possible they got some dirt and or other contaminants on it . Id recheck to make sure you got all the wires connected too .
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Joined: Jul 1999
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Check engine Light
Hdlinerman ,
O2 sensors can be pricey ..The Ford Version is most likely the most $$$ compared to the after market ones . Before you go swapping parts though , make sure thats the problem . Because 95 models are OBII , you ll have to have a code scanner or have someone do it for you . Its cheaper than changing parts .
O2 sensors can be pricey ..The Ford Version is most likely the most $$$ compared to the after market ones . Before you go swapping parts though , make sure thats the problem . Because 95 models are OBII , you ll have to have a code scanner or have someone do it for you . Its cheaper than changing parts .
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Check engine Light
Ensure your cat and or exhaust is not blocked. That may cause the hesitation and the check engine light to flash. At night the convertor will sometimes glow cherry red when it becomes restricted accompanied by the "too damn hot" smell. My 02 sensor on my 96 went bad at 70,000 miles. After using a $3000 Sun scanner (that said change 02 sensor) To get my check light to go out I had to replace both 02 monitors mounted in each of the exhaust manifolds (4.9L) also. The truck ran the same either way. What a ripp-off. All dealer item only parts according to all the local parts people. Ford got me for $180 for the three sensors. (kinda wished I'd popped out the check engine light bulb) Those check engine lights are a money making deal for somebody. Also check your throttle bores, ensure they are clean.
What happens when you accelerate in lower gears? Do you still get the hesitation above 2000 RPM's? Maybe time for a high pressure injector cleaning? Work on the hesitation problem. If the light wont stay on I wouldn't worry about it. Chris...
What happens when you accelerate in lower gears? Do you still get the hesitation above 2000 RPM's? Maybe time for a high pressure injector cleaning? Work on the hesitation problem. If the light wont stay on I wouldn't worry about it. Chris...
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Joined: Jul 1999
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Check engine Light
Chris ,
Cats dont just melt or become clogged for no reason . They generally last the life of the vehicle given that vehicle is serviced on a regular basis . Cats usually melt and die from and over rich condition ...unburned fuel makes a nice little campfire pit in the cat . Vehicle servicing and diagnosis is a buyer beware situation . Most are honest and competent , but its our job to find a shop / mechanic that knows the vehicle and stays on top of the technology . The days of when our fathers changed the plugs and wires to get the old doll to purr are gone . Computer controlled vehicles are here to stay and will only get more complex on par with everything else . As with anything , education is the best defense . The more you know about what makes your vehicle tick reduces the chances of letting some hack or profit sharing parts dude slide one by you . Thats just my opinion ....Ive been wrong a few times .
Cats dont just melt or become clogged for no reason . They generally last the life of the vehicle given that vehicle is serviced on a regular basis . Cats usually melt and die from and over rich condition ...unburned fuel makes a nice little campfire pit in the cat . Vehicle servicing and diagnosis is a buyer beware situation . Most are honest and competent , but its our job to find a shop / mechanic that knows the vehicle and stays on top of the technology . The days of when our fathers changed the plugs and wires to get the old doll to purr are gone . Computer controlled vehicles are here to stay and will only get more complex on par with everything else . As with anything , education is the best defense . The more you know about what makes your vehicle tick reduces the chances of letting some hack or profit sharing parts dude slide one by you . Thats just my opinion ....Ive been wrong a few times .
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Check engine Light
When I was going through my 02 sensor problem a Ford mechanic said to watch for a problem among the 4.9L trucks. The A/C drain tube has been the cause of many a shorted out 02 sensors. It drips condensation on the sensor enough to cause problems. He mentioned a kit I could buy to re-route the drain hose. I passed on the deal. Remember the A/C compressor runs in the mix and defrost modes so its not just a summertime problem. One more thing to watch for. Chris...
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Postmaster
Joined: Jul 1999
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Check engine Light
That sounds plausible Chris ... Mine does drip in that area . I have an F150 w the 4.9l and only had to change the O2 sensor about the mid 90K mile range . Considering where they live and the heat they endure ...Im surprised they live as long as they do ?