Check Engine Light
Thread Starter
|
New User
Joined: Mar 2007
Posts: 2
Likes: 0
Check Engine Light
I have a “Check Engine” issue on my 1992 F150 that I purchased new in ’92 and now has 110,000 miles. It is a 2wd with a 5-speed standard and 4.9L. Starting about 4 years ago, the check engine light would come on intermittently for a few seconds and then go off. It would always start doing it approximately 1 mile from startup and it came on more frequently in hot weather. It was always under low load (cruising on level ground), but never during high load or idle. Right before the light came on, you could feel the truck hesitate slightly, like it was too lean or too rich.
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com
fficeffice" /><o
></o>
I had someone read the codes with a handheld computer and it indicated something was wrong with the oxygen sensor, so I replaced it. The light stayed off for 3-4 weeks and I thought the problem was solved. However, it slowly began happening again until it was happening frequently again during warm weather. I finally had someone else read the codes at a parts store. He said it indicated something was wrong with the throttle body, so I took it off, cleaned it, replaced the gasket, and put it back on. The light stayed off for 3-4 weeks again, and again I thought the problem was fixed. But once again, it slowly started happening again – very seldom in cold weather (<40 deg F), but more and more often in warm weather.
<o></o>
I then had a mechanic read the codes with a Snapon code reader and it indicated something with engine temperature. I was also getting no heat out of my heater, so he recommended that I replace the thermostat. I had done this recently, but I did it again. This had no effect. The light continued to come on and off. I finally realized the heater problem was due to a clogged heater core, so I replaced it. During this replacement, I did nothing else – I didn’t unhook the battery, wiggle spark plug wires, etc. I then had heat AND my light stayed off for 3-4 weeks. But then it slowly started coming on again.
<o></o>
This truck has been well maintained. The plugs, wires and cap were replaced at 66,000 mi. The problem has persisted over a period of 4 years and the symptoms have always been the same: The truck hesitates slightly under low load and the light comes on a few seconds later. Accelerate and the light will go off after a few seconds. It also occurs much more frequently in hot weather than in cold weather.
<o></o>
I read the current codes from the dashboard and they are: KEOE = 522 (Vehicle not in park or neutral during KEOE) and Continuous = 179 (Right side still rich, at leanest adaptive limit, during part throttle). I don’t know why 522 shows up – I had the truck in neutral. However, the 179 seems to make sense. What would this indicate is wrong? I would greatly appreciate any advice.
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com
fficeffice" /><o></o>I had someone read the codes with a handheld computer and it indicated something was wrong with the oxygen sensor, so I replaced it. The light stayed off for 3-4 weeks and I thought the problem was solved. However, it slowly began happening again until it was happening frequently again during warm weather. I finally had someone else read the codes at a parts store. He said it indicated something was wrong with the throttle body, so I took it off, cleaned it, replaced the gasket, and put it back on. The light stayed off for 3-4 weeks again, and again I thought the problem was fixed. But once again, it slowly started happening again – very seldom in cold weather (<40 deg F), but more and more often in warm weather.
<o
></o>I then had a mechanic read the codes with a Snapon code reader and it indicated something with engine temperature. I was also getting no heat out of my heater, so he recommended that I replace the thermostat. I had done this recently, but I did it again. This had no effect. The light continued to come on and off. I finally realized the heater problem was due to a clogged heater core, so I replaced it. During this replacement, I did nothing else – I didn’t unhook the battery, wiggle spark plug wires, etc. I then had heat AND my light stayed off for 3-4 weeks. But then it slowly started coming on again.
<o
></o>This truck has been well maintained. The plugs, wires and cap were replaced at 66,000 mi. The problem has persisted over a period of 4 years and the symptoms have always been the same: The truck hesitates slightly under low load and the light comes on a few seconds later. Accelerate and the light will go off after a few seconds. It also occurs much more frequently in hot weather than in cold weather.
<o
></o>I read the current codes from the dashboard and they are: KEOE = 522 (Vehicle not in park or neutral during KEOE) and Continuous = 179 (Right side still rich, at leanest adaptive limit, during part throttle). I don’t know why 522 shows up – I had the truck in neutral. However, the 179 seems to make sense. What would this indicate is wrong? I would greatly appreciate any advice.
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
To deal with the ECT, I'd replace that sensor first. Also test for vacume leaks. It's also possible you have a sticky injector staying open and causing the rich condition on the right side.
I always got a neutral safety switch error when testing my 89, I think I finally read somewhere that if the initial testing was not complete you also get that error.
I always got a neutral safety switch error when testing my 89, I think I finally read somewhere that if the initial testing was not complete you also get that error.
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
ECT Engine Coolent Tempature
The gas cap problem is usually associated with OBD2 computers and GM OBD1. Part of the on board diagnostics emissions setup requires a vacume in the fuel tank. I don't belive EEC-IV need it.
The gas cap problem is usually associated with OBD2 computers and GM OBD1. Part of the on board diagnostics emissions setup requires a vacume in the fuel tank. I don't belive EEC-IV need it.
