CODE 44 - Lean Exhaust? Low oxygen sensor voltage..350 TBI code

[Southern Pride]

So guys I originally had a code 32 egr failure...fixed that
Now I have a code 44 Lean exhaust- Low o2 sensor voltage...Now...I just put a TB spacer on and powercharger tonight with great results but the CEL did not necessarily come on tonight, so I don't necessarily think that somehow has anything to do with it as they would mention it might cause this.

One thing though I did just have my cats hacked off welded back on and raised because of my realift. Point being when they did this, the welding job was just TERRIBLE and before I may have a had a little exhaust leak, well it's really now...Not just terrible but definitely more noticeable than before...Also there is like a 1" space in between on the doughnut gasket on my exhaust manifold and the exhaust connection on the passenger side.

My question is, is this more less a bad o2 sensor? Or is it just reading lean because I have a bad exhaust leak? OR should I replace both the o2 sensor and get the exhaust leak fixed? Anyway, I wouldn't be as concerned with a rich mixture but lean is not good. Although it may not really be running lean but thinks it is because of the exhaust leak...but really though I have no idea and limited mechanical knowledge so this is the reason for the thread. Based on my info thought one of you may be able to help me out!! Thanks guys!

Griffin

 

[Southern Pride]

Alright fellas, I found this information on google :

"The code 44 for lean exhaust is most likely caused by one or more of the following:

1.) O2 sensor wire - Sensor pigtail may be mispositioned and contacting the exhaust manifold.

2.) Check for an intermittent ground wire between connector and sensor.

3.) Poor ECM to engine block ground.

4.) MAF Sensor - A MAF sensor that causes the ECM to sense a lower than normal airflow will cause the system to go lean. Disconnect the MAF sensor. If the lean condition is gone then replace the MAF sensor.

5.) Vacuum leaks can cause a lean condition and/or possibly a high idle. Check for cracked hoses a bad gasket or a faulty EGR or PCV Valve.

6.) fuel pressure - system will go lean, if pressure is too low. It may be necessary to monitor fuel pressure while driving the car at various road speeds and/or loads to confirm.

7.) Clogged injector or lean injector - perform an injector balance test.."



It doesn't say anything about exhaust leaks really...but #5 concerns me because of the mods I did tonight(tb spacer and powercharger). Maybe I messed a gasket up somewhere? I am positive I had the main TBspacers gaskets on correctly...None of it was hanging out over the edges on the TBspacer nor on the powercharger...Sucks because of that I think I'm going to have to take it all apart again tomorrow and make sure the gaskets are on correct, which it seems like I'd know for sure if one was because I'd be able to see it not fit correctly...frustrating!

 

[stroker52]

i would slap a new O2 on and see if it clears up... but you need to fix the exhaust for sure!! your killing power if its a bad leak...

 

[Southern Pride]

Yeah...damn it. I really don't want to take the spacer and powercharger back apart but looks like I may have to but if I get a strong opinion that it's more likely to be the ehxaust leak or o2 then I won't.

I mean just scenario wise say somehow the spacer or powercharger gasket is off...could it even cause a problem @ the o2 sensor and wouldn't the truck run and idle like hell?

 

[stroker52]

i had the O2 plug up in my 96 then the CEL came on, i pulled the code and it came back right bank lean.. i shot it with some brake clean and it worked for about a year...

spay some carb cleaner around the base of you TB and see if the idle goes up... thats the easy way to see if you have a vac leak...

 

[Southern Pride]

Oh really? So I just start the motor @ idle and spray the carb cleaner all around there and if the idle bumps up then I have an exhaust leak?

One problem I had was not with the TBspacer gaskets but the powercharger gasket that came for the base of the powercharger that mounts on top of the TB the gasket was thick 3/4 of the way around and then it got really thin about 1/4 of the way around??? I need to ask my buddy who did these mods about that....I will try the carb cleaner trick. Hopefully the idle kicking up will be pretty noticeable.

 

[Toms94z71]

If the exhuast leak is near or in front of the o2 sensor then it can let fresh air into the exhaust, and make the o2 sensor think it's running lean from the added o2 in the exhaust. Also a bad sensor or connection can cause low voltage.

 

[Swaggerwagon]

i had a code 44 lean exhaust and low o2 voltage last year, ended up being a bad fuel pressure regulator....

 

[Southern Pride]

Yeah but do I have a fuel pressure regulator on my truck? Or isn't that an aftermarket add on? I have been meaning to change my fuel filter as I haven't in years...Could that cause it to be lean? Mainly I have a terrible exhaust leak all around this o2 sensor so I'm thinking that is what's causing it.

Also guys if it was caused by a vacuum leak at my TB wouldn't the truck run and idle bad??? Cuz it's never ran better than it is right now and no ones been able to answer that for me yet...

 

[MOBS]

Bad vac leaks CAN cause idle issues. Is your idle smooth or does it move around after ya goose the gas, like go down then ease up then back down a bit.....sort of like it can't find it's perfect idle position for a few seconds.