Help trouble code H44...
11-20-2006, 03:22 PM
#1
Safety Car
Thread Starter
Help trouble code H44...
I got this code the manual says its a left o2 sensor lean condition. I replaced this once before about 1000 miles ago. Could it be possible that its gone bad? What causes O2 sensors to fail?
11-20-2006, 03:32 PM
#3
Safety Car
Thread Starter
My manual says the same thing but how do you check for exhaust leaks? I'll have to get a fuel press. guage to check the fuel pump also. I have no clue.
11-20-2006, 05:23 PM
#4
Racer
Member Since: Jun 2006
Location: Elkton MD
Posts: 408
Likes: 0
Received 0 Likes
on
0 Posts
Left bank lean
Is it possible that you have a lean condition (failed injector, vacuum leak, etc.) in the left bank? Or does the car run bad only in closed loop (your other thread)???.
11-21-2006, 01:47 AM
#5
Safety Car
Thread Starter
It starts up and idles fine in park but when you put it in gear the idle goes to crap. It doesn't die though. The check engine light comes on and the idle is smooth again. I'm thinking either a clogged fuel filter, bad fuel pump. The FSM says it could be the left O2 sensor, lean injectors, exhaust leaks or fuel contamination. Any ideas on where to start?
11-21-2006, 02:32 AM
#6
Racer
Member Since: Jun 2006
Location: Elkton MD
Posts: 408
Likes: 0
Received 0 Likes
on
0 Posts
Rough idle
The O2 sensors won't cause a problem in open loop when the engine is cold. Is the idle bad right away or only after warm up? If it's ok cold, sounds like an O2 sensor. Check that the wiring to the O2 sensor isn't burnt or disconnected, etc.
Exhaust leaks ought to be noticeable, especially if you can get the car on a rack. Or use a 4' length of garden hose; one end in your ear and put the other end at various points along the exhaust and around the engine.
I have no experience but many have posted here about checking injector resistance and that they need to be in the 14 ohm -/+ 2 range. Further "all injectors need to be about the same".
Bad gas is a booger to diagnose. I've had two doses years ago and pulled my hair out looking. Eventually changed the filter and in the process drained the remaining gas into a can. New gas gave the cure. But what a pita. And dangerous.
Is the idle air control valve listed as a potential cause of lean? That's another place to look.
Good luck.
Exhaust leaks ought to be noticeable, especially if you can get the car on a rack. Or use a 4' length of garden hose; one end in your ear and put the other end at various points along the exhaust and around the engine.
I have no experience but many have posted here about checking injector resistance and that they need to be in the 14 ohm -/+ 2 range. Further "all injectors need to be about the same".
Bad gas is a booger to diagnose. I've had two doses years ago and pulled my hair out looking. Eventually changed the filter and in the process drained the remaining gas into a can. New gas gave the cure. But what a pita. And dangerous.
Is the idle air control valve listed as a potential cause of lean? That's another place to look.
Good luck.
11-21-2006, 01:12 PM
#8
Safety Car
Thread Starter
Ok fuel pressure is at 42 psi with the key on. At idle it drops to 39 psi. It holds at 40 for 30mins. Does this rule out the fuel system? Could a bad iac cause the code H44? Or maybe the map sensor? The FSM says to check these with the tech 1 but this i do not have.
11-21-2006, 04:32 PM
#10
Racer
Member Since: Jun 2006
Location: Elkton MD
Posts: 408
Likes: 0
Received 0 Likes
on
0 Posts
Bad left O2 sensor
Look a the simple sources first, also the easy to measure.
Probably can rule out system wide failures since the left side is giving the error. (Note emphasis on PROBABLY)
So that means the gas is likely OK, the IAC is likely OK, the AIR (air injector reactor) is likely OK.
Further, you've shown that the fuel pressure is normal so fuel system is OK up to the injectors.
So what's left?
1-Exhaust leaks
2-O2 sensor wiring and the sensor itself.
3-The injectors
4-Intake leaks
5-Crankcase leaks
Do the easy stuff first.
1-Get a 4' piece of hose and listen for exhaust leaks. (I think this is a long shot)
2-Look at the O2 sensor and wiring. The FSM mentions making sure the wiring going into the sensor is clear to permit reference O2 entry, not kinked and not grounded by scraping or contact with the exhaust.
3-The injector test described on FSM pages 6E3-C2-18 to 23 looks daunting but can be abbreviated for a quick look. Measure the resistance of the left side injectors (11.8-12.6ohms at 50-90 degreesF). Betcha find it this way if it's an injector (or maybe a couple of them).
In a thread a few weeks ago, someone mentioned letting the injectors pee into 4 paper cups would reveal 'non-flow' injectors. This sounds easy but don't catch fire to everything. I looked but can't find the thread.
4-Chase Intake leaks with a garden hose in the ear to look for hissing leaks of intake air. This isn't usually successful so dribble some NON flammable brake clean (or a little water) around the intake/head seams on the left side. If it's an intake leak, the lean condition should clear up briefly.
5-Crankcase leaks - sounds like a big booger to do.
You mentioned the roughness starts when putting into gear. Refine that a little: Does the engine run smoothly until warmed up (in or out of gear)? If so, it's almost surely the O2 sensor. If the engine runs rough cold, it's likely an injector. Try the easy/likely stuff first.
Hope this helps
BTW thanks for the 8D9 page #
Probably can rule out system wide failures since the left side is giving the error. (Note emphasis on PROBABLY)
So that means the gas is likely OK, the IAC is likely OK, the AIR (air injector reactor) is likely OK.
Further, you've shown that the fuel pressure is normal so fuel system is OK up to the injectors.
So what's left?
1-Exhaust leaks
2-O2 sensor wiring and the sensor itself.
3-The injectors
4-Intake leaks
5-Crankcase leaks
Do the easy stuff first.
1-Get a 4' piece of hose and listen for exhaust leaks. (I think this is a long shot)
2-Look at the O2 sensor and wiring. The FSM mentions making sure the wiring going into the sensor is clear to permit reference O2 entry, not kinked and not grounded by scraping or contact with the exhaust.
3-The injector test described on FSM pages 6E3-C2-18 to 23 looks daunting but can be abbreviated for a quick look. Measure the resistance of the left side injectors (11.8-12.6ohms at 50-90 degreesF). Betcha find it this way if it's an injector (or maybe a couple of them).
In a thread a few weeks ago, someone mentioned letting the injectors pee into 4 paper cups would reveal 'non-flow' injectors. This sounds easy but don't catch fire to everything. I looked but can't find the thread.
4-Chase Intake leaks with a garden hose in the ear to look for hissing leaks of intake air. This isn't usually successful so dribble some NON flammable brake clean (or a little water) around the intake/head seams on the left side. If it's an intake leak, the lean condition should clear up briefly.
5-Crankcase leaks - sounds like a big booger to do.
You mentioned the roughness starts when putting into gear. Refine that a little: Does the engine run smoothly until warmed up (in or out of gear)? If so, it's almost surely the O2 sensor. If the engine runs rough cold, it's likely an injector. Try the easy/likely stuff first.
Hope this helps
BTW thanks for the 8D9 page #
11-21-2006, 05:44 PM
#11
Safety Car
Thread Starter
No problem. I listened for exhaust leaks and I don't see or hear any. I also checked for vaccum leaks, intake leak etc, which it doesn't appear to be the case. No leaks were found. I unplugged the o2 sensor and it looks like there is a slight film of oil on the connector and the wires look to be ok. The O2 sensor is a bosch unit with about 1000 or less miles on it. Would the fact that there is oil inside the connection be the cause of these intermediate problems? Should I replace them with denso O2's instead?
11-21-2006, 06:37 PM
#12
Racer
Member Since: Jun 2006
Location: Elkton MD
Posts: 408
Likes: 0
Received 0 Likes
on
0 Posts
O2 sensor oil
Can you see where the oil came from? Inside or did it get dripped on?
It's got to be really difficult to tell the difference. The FSM talks about the need for O2 to get in "via the wires" so oil on the connector could be really bad news. Try cleaning it up (NON flammable brake clean works wonders) and see if it works. Rubbing alcohol would work as a cleaner but it's a little flammable. Be sure to use it only on cool surfaces. Clean both sides of the connector.
While you're under there, try to see where oil might have dripped from.
If you need to replace the sensor, the brand isn't crucial. If you can change it yourself the cost isn't too bad.
It's got to be really difficult to tell the difference. The FSM talks about the need for O2 to get in "via the wires" so oil on the connector could be really bad news. Try cleaning it up (NON flammable brake clean works wonders) and see if it works. Rubbing alcohol would work as a cleaner but it's a little flammable. Be sure to use it only on cool surfaces. Clean both sides of the connector.
While you're under there, try to see where oil might have dripped from.
If you need to replace the sensor, the brand isn't crucial. If you can change it yourself the cost isn't too bad.
11-21-2006, 06:47 PM
#13
Safety Car
Thread Starter
Looks like the sensor got dripped on and i traced the leak to the rear of the intake. Not a very bad leak but a leak no the less. The problem comes and goes and right now its running fine. I'll try and clean the connections. I'll probably go ahead and order a new sensor just to ease my mind.
11-24-2006, 02:37 PM
#14
Safety Car
Thread Starter
Replaced the Left O2 with the denso unit and all is good (so far anyway). I also cleaned the connectors as well. Now for fixing that *@&% intake oil leak. 
11-24-2006, 02:40 PM
#16
Race Director
Originally Posted by JJ 86
Looks like the sensor got dripped on and i traced the leak to the rear of the intake. Not a very bad leak but a leak no the less.
11-24-2006, 09:10 PM
#18
Pro
Member Since: Jun 2004
Location: Mandeville, LA / Clemson, SC
Posts: 520
Likes: 0
Received 2 Likes
on
2 Posts
I had the same EXACT problem with my 94. It turned out to be an oil fouled O2...It only took me three O2s to figure that out!! So keep an eye on the new one and make sure that no oil gets on it.
