Hi everyone, couldn't change the main title of my previous post so I just recreated it.

Corrections from previous post: (spark plugs are fine)
I took out one of my Bosch Platinum plugs to check its gap using the one of the round gap metal readers and it said the gap was at .037 (2 off the norm 0.035) Consequently today I went out and purchased one of the wire gap checkers and that is the accurate one. Don't use those round ones (like the autozone ones) they are off!!! The wire one indicated that the gap was fine.

Symptoms:
- Car is hesitating/stumbling when I am at a light. Feels like its going to shut off but doesn't.
- Code 44 Just popped up which indicates lean exhaust (As per the 02 Sensor)

Changes:
- Checked my plugs they are fine (Only 20k)
- I just swapped in a new fuel filter (previous one had 12k) yesterday seeing if that fixed the hesitation but it didn't when I test drove it. After I got back from the test drive the Service Engine Light came on and gave "Code 44".

Manual says it could be:
- 02 sensor (I don't think that is the case since car is hesitating)
- MAP Sensor
- Lean Injectors (Car has 107k on it)
- Fuel Pressure
- Exhaust Leak

 

I don't think it's an exhaust leak. It would have to be huge, and at that point you'd know it was there.

You can check fuel pressure by renting or buying a fuel gauge from an auto store, and screw it onto the schraeder valve on the fuel rail...passenger side

The 02 sensor would be the next easiest/cheapest step (you have to go at these things in terms of simplicity, lol. No use in buying brand new injectors only to find out its a 20$ sensor). I think they are all of what, 15-20$ at an autozone? Besides, if it hasnt been changed in a while, it's a good thing to get done.

Not sure that injectors really go "lean" per say. Maybe clogged with dirt and grime, blocking flow? In which case I would run some seafoam through the tank first to see if that clears much up. Worse comes to worse, you can get a stock OEM set, but I think that would hit the pocket hardest given your options.

If I were you, I'd also check for vacuum leaks. The smallest one could cause a world of problems. Go ahead and check the small stuff and report back.

 

Hey LesPaulGoth thanks for the reply.

I am totally in that same mind frame. I don't have the cash to take the car in which is killer. I have the manual but that doesn't give me all the how to diagnose knowledge, lol.

The fuel guage idea, cool I didn't know it was that easy. I will check auto zone see what they have. As far as the vacuum leaks is there anyway or tutorials out there that show how that is done?

 

You can also get a vacuum gauge at autozone, I think they are about $20. You hook it up to a vacuum port on the motor and record how much vacuum the engine is pulling. You want a reading in the high teens. If it's lower, start looking for the leak. Or, you could just follow your vacuum lines and visually inspect them from the start. You are looking for the thin soft rubber hoses that are around a quarter inch in diameter. A few run from the charcoal canister, some to the manifold, one to the MAP sensor, cruise control...may be others.

Edit: If you are strapped for cash, just be careful not to damage the packaging when taking the gauge out, and return it if the vacuum reading checks out . Man, I think i've saved over 100$ doing that. "I need to return this...wrong part", they never even think twice about it. Hell, I even bought a short serpentine belt to bypass a few pullies when I went to the drag strip, then returned it when I got back home and said "yeah this was the wrong length".

 

You're getting a lean exhaust reading and throwing a code 44 while stumbling at idle and a hesitation upon throttle opening.

Have you thought about replacing your Oxygen sensor?

My car was doing the same thing to me once when I switched in a new O2 sensor that was apparently DOA. I had to 2-foot the car until I finally figured out why it would surge at idle, stumble, hesitate, etc. Bosch 1-wire O2 for $20ish and all was well.

 

Hi Red, thanks for the reply. Those are my exact symptoms. I am going to head to autozone now and see how much that sucker costs...I thought the 02 sensor was more around 50 bucks...Im outside checking for vac leaks by checking some of the hoses etc..nothing yet...

 

good luck getting that thing out of the header, ive been soaking mine in pb blaster for 2 years and still with a socket i cant get it out,,, ive given up

 

3' crescent wrench and a little muscle will do the trick, and geeze, put some effort into it


The 50$ o2 sensors are typically your 2-3 wire heat proof sensors. Luckily, our cars only have the 1 wire.

 

Well I just got done changing the oxygen sensor it was a pain in the rear. I spent a lot of hours on it. I had to go buy a few wrenches to, that had a different curves. I got it from the bottom of the car. Removed the boots on my plugs and the gas line attached to the frame so i could turn my wrench easier. Of course I heated up the engine for a good 10 minutes to get the sucker loose and I hit it with liquid wrench. I left the battery disconnected and will reconnect tomorrow. Read the cpu had to relearn in a few different posts and the book mentioned it as well.

02 sensor ran me 25 bucks I also picked up the fuel pressure testing gauge ($35) bucks guy at store gave me a courtesy 10% off I was like damn that was nice of him! I haven't opened the gauge yet going to test the 02 sensor first. I will update my post this weekend.

 

$25 aint bad. And remember, keep that packaging on the gauge tidy so you can take it back

 

Guys I changed the 02 Sensor on the car and left the battery unplugged overnight. I read that the ECM had to relearn in the manual. I took the car out the following day for like a 15 minute trip and its running smooth now. But I don't know if that is just because the ECM is still learning etc...Anyone know how long it takes the ECM to relearn?

 

If it's running well when warm, it's fixed. O2 sensor closed loop at idle will "learn" short term within a few seconds when warmed up fully and already running for a few minutes (i.e. if you restart it warm, it takes time to enter closed loop, but once it's in closed loop, it's fast). Long term should take less than a minute, but some calibrations don't allow leaning out for the long term (aka Block Learn, or BLM), in the idle cell, at key off. This means each restart it'll be back up to 128, and then slowly lean out once closed loop starts (if problem persists).

 

Feels good again doesn't it

 

Red, yup she feels nice and smooth again