hmm...code 44?
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
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From: Jasper Texas
hmm...code 44?
Still havent got anywhere on this! No one seems to have a clue! please take a look at my newest post.
Today while cruising, the check engine light came on and my instantanious gas mileage dropped to ~8mpg. It stayed like this for a minute or so, then returned to normal for the rest of the 80 miles. Checked codes, came up with a 44...which means lean exhaust present. It said to check the o2 sensor and fuel pressure, both are fine, everything in the fuel system is new, and I have tested many times. The o2 is new also. It also happened while in open loop, I had just started driving, so thats confusing also. Any ideas out there? TPS checks out ok, but maybe its bad....or what about the computer?
I'm lost.
Today while cruising, the check engine light came on and my instantanious gas mileage dropped to ~8mpg. It stayed like this for a minute or so, then returned to normal for the rest of the 80 miles. Checked codes, came up with a 44...which means lean exhaust present. It said to check the o2 sensor and fuel pressure, both are fine, everything in the fuel system is new, and I have tested many times. The o2 is new also. It also happened while in open loop, I had just started driving, so thats confusing also. Any ideas out there? TPS checks out ok, but maybe its bad....or what about the computer?
I'm lost.
Last edited by cwyates4; Oct 23, 2008 at 01:11 AM.
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
Actually, i had the same thing happen to me last thursday morning...that time, it wasn't during open loop though. I had been cruising for a good 45 minutes.
The only symptoms I feel, is that when the CEL lights up, the car actually feels like its running slightly smoother and has more power. Everything else is normal except the light, and horrible gas mileage.
Here's what I think: I think the TPS is sending false readouts to the computer, like saying we are at half throttle or more. The tps position is what the dash uses to do MPG. So, the computer is seeing half throttle, but the o2 isn't agreeing, its readings are too "lean" for supposedly half peddle. Anyone follow me here?
But...I have tested the tps on many occasions...it reads at .54 at idle, 4.5 at WOT, and the volts rise smoothly as I open the throttle.
The only symptoms I feel, is that when the CEL lights up, the car actually feels like its running slightly smoother and has more power.
Everything else is normal except the light, and horrible gas mileage. Here's what I think: I think the TPS is sending false readouts to the computer, like saying we are at half throttle or more. The tps position is what the dash uses to do MPG. So, the computer is seeing half throttle, but the o2 isn't agreeing, its readings are too "lean" for supposedly half peddle. Anyone follow me here?
But...I have tested the tps on many occasions...it reads at .54 at idle, 4.5 at WOT, and the volts rise smoothly as I open the throttle.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
I think your logic is faulty.
Here's what I think: I think the TPS is sending false readouts to the computer, like saying we are at half throttle or more. The tps position is what the dash uses to do MPG. So, the computer is seeing half throttle, but the o2 isn't agreeing, its readings are too "lean" for supposedly half peddle.
Here's what I think: I think the TPS is sending false readouts to the computer, like saying we are at half throttle or more. The tps position is what the dash uses to do MPG. So, the computer is seeing half throttle, but the o2 isn't agreeing, its readings are too "lean" for supposedly half peddle.
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Advanced
Joined: May 2003
Posts: 96
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From: Moreno Valley CA
I had the same thing happen to my 87. It was one of those on again and off again things. After checking everything out I went to the oxygen sensor circuit. I found .00021 volts on the circuit. There is supposed to be .34 volts on the circuit with the key on engine off. I replaced the circuit, measured again and did have .39 volts to the oxygen sensor. No more codes. I don't know what year your Vet is, however, the oxygen sensor does need a reference voltage. It is a easy check to make. I never did like the way the engineers routed the wiring harness over the back of the engine.
Gary
Gary
Thread Starter
Melting Slicks
Joined: Jan 2008
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From: Jasper Texas
thanks though.
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
Did it again today thirty miles into my trip. RPMs rise ~150 and engine smooths out when the CEL comes on. Happened for about two minutes and returned to normal. Thoughts?? Only code is a 44.
Thread Starter
Melting Slicks
Joined: Jan 2008
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From: Jasper Texas
CTS is new.
No i dont and i do need a heated O2, but i dont think that the car is going between open and closed loop.
No i dont and i do need a heated O2, but i dont think that the car is going between open and closed loop.
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
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From: Jasper Texas
Can I plug a tech 1 in and use it while driving? I'm not sure, but does the tech 1 read aldl info, such as iac counts, tps voltage, etc.?
What doesn't make sense to me is...why the drop in gas mileage...but a lean exhaust code is thrown...that makes no sense at all! When it is acting up, and the cel isnt on, the mpg goes down to 8, then when the cel lights, it rises to 12, and the engine surges just a little.
Other than that, the only problem I'm having with the car is a rough idle/stalling when I first start it up in the morning, or after its been sitting for longer than 6 hours or so.
Could it just be the dang computer!!??
What doesn't make sense to me is...why the drop in gas mileage...but a lean exhaust code is thrown...that makes no sense at all! When it is acting up, and the cel isnt on, the mpg goes down to 8, then when the cel lights, it rises to 12, and the engine surges just a little.
Other than that, the only problem I'm having with the car is a rough idle/stalling when I first start it up in the morning, or after its been sitting for longer than 6 hours or so.
Could it just be the dang computer!!??
Team Owner
Joined: Jul 2004
Posts: 28,475
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From: Hartford WI
I think you can use the Tech One for live data gathering, IIRC.
As to the gas mileage, I wouldn't believe it for a second. On my Ford Excursion diesel, other board members call it the "Lie-O-Meter" for a reason. Currently, my car is looking at 40 mpg if that thing is to be believed.
Have you checked fuel pressure and spark?
As to the gas mileage, I wouldn't believe it for a second. On my Ford Excursion diesel, other board members call it the "Lie-O-Meter" for a reason. Currently, my car is looking at 40 mpg if that thing is to be believed.
Have you checked fuel pressure and spark?
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
yes on fp, no on spark. But on the mpg thing, It normally reads 22mpg, but plummets when this problem is happening, then returns when it goes away...it has a significance, whether the mpg is actually true or not. That is why I think its the computer, or the tps. but who knows?