92 S-10 Blazer Code 44

Ok here is the goods.......I looked around on the site b/c I coulda sworn there was a post about code 44 before but I can't find it. I drove home on fri. which is 113 miles about and had no problem at all for the main part until the last 10 miels came up. I was on mainly highway with cruise control radio on lights on and had no problem. But the last 120 miels I got off the highway and then needed my high beams so I turned them on and as soon as I did the engine light came on. I took it home turned it off thenr estarted to see if the light would stay on. Nope the light was now off. So the enxt day took to Autozone got it scanned and got code 44 coming up.

They said it could be vacum related, low votlage at my O2 sensor, or soemthing else. But I rememebred many posts on here that most tiems they just Bullshit you at autozone. So ym question is this....Why did I get that code? I replaced ym O2 sensor about a year ago. Could it be soemthing else? Also I drove the same 113 miels back to college today and had no major problems except my radio turned itself off......That says to me maybe my alternator. But 10 mins. later I was able to turn ym radio back on and had no other problems.

Recent work done........
ALL fluids have been drained and refilled.
4x4 works good but the computer gets messed up when switching back to 2 Hi from 4 wheel. Let it sit overnight and it is fine. The vacum is fine b/c it does disengage the front I know b/c I tried it in the snow and sat there and spu than switched abck and went.
Starter was rebuilt in December.

Work it needs......
Replace U Joints. and figure out why front end vibrates.

Check all connections going to and from the computer under the glove compartment.

Make sure they are clean and dry.

Code 44 means lean exhaust. Either the o2 sensor took a dump or the engine is running lean at times.

Code 44 does mean lean exhaust and I highly doubt it is the O2 sensor causing the problem.

More than likely it is doing its job.

Factors to consider:

Fuel Filter plugged.

Timing advanced too much. Remember to unplug the beige and brown timing wire from the PCM under the glove compartment before you check the timing with a timing gun.

ok thanx I'll check it out.