cel problem
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cel problem
hey all, forgive me if this has been posted, but I can't find answer, at least not for how it happened.
I have a 99 expy with the 5.4 triton. I went to get the oil changed, and while I was at it had the air filter changed. about 50 miles later, CEL came on.
I noticed when I hit on ramps and reach a speed of about 50 and the tac is still under 2000, it misfires. At first I thought it was in my head, but it started progressively getting worse. While idling at rest, it's fine.
I went to Autozone and got a code reading of PO171 and PO174.
came here and followed some advice and cleaned the MAF sensor. That didn't work, so I changed the MAF sensor. still didn't work. I have checked the hoses for vacuum leaks, all good.
Now, I know I can change the o2 sensors, but I don't buy it. doesn't make sense, because it was working fine, until I changed the airfilter and had the oil changed. Of course, I've seen freaky things happen before.
any help would be appreciated
thanks
A. Halcon
I have a 99 expy with the 5.4 triton. I went to get the oil changed, and while I was at it had the air filter changed. about 50 miles later, CEL came on.
I noticed when I hit on ramps and reach a speed of about 50 and the tac is still under 2000, it misfires. At first I thought it was in my head, but it started progressively getting worse. While idling at rest, it's fine.
I went to Autozone and got a code reading of PO171 and PO174.
came here and followed some advice and cleaned the MAF sensor. That didn't work, so I changed the MAF sensor. still didn't work. I have checked the hoses for vacuum leaks, all good.
Now, I know I can change the o2 sensors, but I don't buy it. doesn't make sense, because it was working fine, until I changed the airfilter and had the oil changed. Of course, I've seen freaky things happen before.
any help would be appreciated
thanks
A. Halcon
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You could've knocked something else loose in the area when you changed the air filter, so that's something to look into. But I'd be more inclined to think that the air intake duct from the air filter housing to the throttle body has a leak. Either it cracked or it's loose at one of it's ends. Any air that enters this duct after the MAF will cause a lean condition in both banks 1 & 2.
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problem solved; albeit wasn't a crack in the housing and tubes after the MAF.
I finally had enough of the problem that I took it to the mechanic. according to him, 3 coils were shot. I felt it to be too coincidental, but honestly, my patience ran out and I had him replace them along with the spark plugs and wires.... $500, but whatever. small price to pay for peace of mind.
thanks for the help guys
I finally had enough of the problem that I took it to the mechanic. according to him, 3 coils were shot. I felt it to be too coincidental, but honestly, my patience ran out and I had him replace them along with the spark plugs and wires.... $500, but whatever. small price to pay for peace of mind.
thanks for the help guys
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From: St Louis
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hmmm! Not that I'm trying to protect the integrity of the mechanic, but I did have major misfires.
When I went to autozone, like a dummy, I had the codes erased. I went to one mechanic and he said its better I wait until the codes come back. After another 100 miles of driving, they never came back. (yes I purposely drove around trying to get those codes back). So, not only did those codes not come back, but the misfiring was starting to get worse.
I stopped in at the mechanics yesterday afternoon and finally got it fixed.
coincidence that changing the air filter and coils go out? hmmm! I find it highly suspect. Did I get taken? I don't know considering the codes never came back after a hundred miles of driving, aimlessly
When I went to autozone, like a dummy, I had the codes erased. I went to one mechanic and he said its better I wait until the codes come back. After another 100 miles of driving, they never came back. (yes I purposely drove around trying to get those codes back). So, not only did those codes not come back, but the misfiring was starting to get worse.
I stopped in at the mechanics yesterday afternoon and finally got it fixed.
coincidence that changing the air filter and coils go out? hmmm! I find it highly suspect. Did I get taken? I don't know considering the codes never came back after a hundred miles of driving, aimlessly
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Joined: Jan 2004
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From: St Louis
When I went to autozone, like a dummy, I had the codes erased. I went to one mechanic and he said its better I wait until the codes come back. After another 100 miles of driving, they never came back. (yes I purposely drove around trying to get those codes back). So, not only did those codes not come back, but the misfiring was starting to get worse.
I stopped in at the mechanics yesterday afternoon and finally got it fixed.
coincidence that changing the air filter and coils go out? hmmm! I find it highly suspect. Did I get taken? I don't know considering the codes never came back after a hundred miles of driving, aimlessly
Steve
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Sorry if it wasn't clear
I did put this in the original post
Project, I do feel a little more confident about my decision, after reading your post, thanks
I did put this in the original post
I noticed when I hit on ramps and reach a speed of about 50 and the tac is still under 2000, it misfires. At first I thought it was in my head, but it started progressively getting worse. While idling at rest, it's fine.