In a previous post, I detailed the problems I'm having with my '99
K3500. Basically, it boils down to.....on a long trip I started having
performance issues (won't pull hills, very bad mileage). Hooked it up
to a scanner and got a code of P0171 - Bank 1 Lean Fuel Trim. Since
all four oxygen sensors are identical, I swapped the two pre-cat
sensors to see if it would transfer the problem to the other
(passenger) side. It did not. I noted that the driver's side sensor
Started pulling plugs and 3 and 7 are sooty. 1,5,2,4,6,8 look normal
for @30,000 miles.
So, as far as I can tell, I'm down to clogged injectors, bad spark plug
wires, bad plugs, or bad distributor cap/rotor.
If it turns out to be the injectors - as all else is replaced with
relative little cost - which two is it going to be? I figure 3 and 7
are sooty because the computer is dumping fuel into Bank 1 and I'm
getting incomplete combustion. That would leave 1 and 5 to be the
clogged injectors, right?
Interested in what you think. Thanks in advance.