I'm hoping to see if anyone can shed some light.
I made the potential mistake of buying a highish mileage cheap LS430 with issues, and I'm getting to the end of my tether.
So, long story short, the car runs absolutely spot on for the first 10 minutes when the engine is cold. Loads of grunt, smooth as you like, happy days.
Once the car gets a little warm, and goes into what I will assume for now is closed circuit running, its gets rough.
At idle in D the large sputters and lurches and is lumpy as holy hell.
In driving it feels like its running on around 3-5 cylinders until you give it a good old kick in the pants and get it revving and feels/sounds like cylinders are being lit as the revs build. Like the engine is slowly coming to life/waking up
If I manually shift around the box and keep the revs up over 2000rpm it settles down and becomes a delight again.
Now for the list.
P0300 - random misfire
P0301-0308 - I'll get codes for a few different misfires on any/all cylinders, usually 3 or 4 stack up between resets.
P0141 - O2 sensor heater circuit malfunction in bank 1 sensor 2 - this has been replaced, and the code persists
P0171 - Bank 1 too lean
P0601 – Engine control module (ECM) -memory check sum error
P0003 - Fuel Volume Regulator Control Circuit Low
P0101 - Mass Air Flow Sensor Circuit Range/Performance
I also regularly get the flashing MIL lamp, but not in consistent driving conditions, i.e. can happen on light throttle cruising, heavy throttle acceleration or anything in between, usually only for a few moments.
So, what have I done to try and sort these?
Naturally, i assumed misfires = weak spark etc, so plugs and coils have been changed. No change.
I was seeing the 0141 code a lot, so changed B2S2 O2 sensor. No change.
I found an earth strap broken and connected to nothing under the car when changing said O2 sensor, so have replaced.
I've cleaned the MAF, which was quite dirty, and seemed to smooth things out a little, for a short time.
So yes, I'm at a loss! Anyone have any ideas before I consider drastic action?!