1999 suburban sometimes runs good

[90Tank]

I'm working on a 1999 suburban k1500 with a 350. Sometimes it runs great but more often than not it seems like it is misfiring. It also occasionally acts like the battery is dead but after its jump started you can shut it down and it will crank up fine. It usually runs and revs fine in park and the problems start when put in gear. Every once in a while it just seems to catch and will start running fine. There is a strong gas smell when it is acting up as well. When it was bought it ran OK for having clogged cats. I have half a catless dual exhaust installed, had plugs, wires, cap and rotor done about a year ago although there is some corrosion on the cap, coil was replaced, upgraded the fuel injection to the mpfi spider and replaced fuel pump before that. I'm running out on ideas for what the problem might be. I'm planning on testing the knock sensor next. There are also no check engine lights.

 

[90Tank]

I took another look at the distributor and when I twist the rotor it seems to have quite a bit of play in it. Could the distributor gear be worn out? I couldn't put a timing light on it because I can't see the timing tab on the timing cover.the knock sensor does have continuity between it and the battery although I have to replace it because I broke the plastic.

 

[evilunclegrimace]

Check for stored codes

 

[90Tank]

Checked and cleared stored codes and they came back after a test drive. P0300, p0304, and p0152

 

[90Tank]

Today I checked codes and it was throwing those plus p0102. I cleaned the maf and took it for a drive. It was a little better. It's still throwing p0152. I disconnected the battery while I'm checking the o2 sensor.

 

[90Tank]

I found that a ground wire that should be connected to the back of the passenger side head was not connected so I grounded that wire and disconnected the battery. It runs great now. Still have the p0300 code and now have p0174.

 

[90Tank]

And today it's back to misfiring