Bank 1 sensor malfuncatoin/lean fuel/slow to react
what engine, no engine size stated so i must generalize. (hard)
you got a CEL then pulled the DTC, bravo that.. well done!@
B1S1 or B1S2, posting the actual DTC wins here,
any other DTC'S or running symptoms?????????????????????
my guess is B1S1 , due to lean lookup. bank 1 sensor 1.
S1 is the keystone of engine fueling (at idle or steady cruise) .
It determines the final air and fuel air mixtures.
the sensor can be bad.?
or any cracks in the exhaust near it.????? (fresh air is 20% oxy)
or engine really is lean.
see , 2 logic reasons, sensor bad or good and is lean for real.
if car has 100k on it, its due, for a change, anywhy
so do that.
then if it comes back, then it real (no cracks)
why is my engine really real.
its lean for a large number of possible reasons...
1: low fuel pressure.
2: MAF stuck high, or if MAP car, map reading to high.
in simple English the air sensors are fibbing showing Low air when it really air.
the air sensors. are the prime sensors.
all fuel is injected based on them. (and temperatures)
3: air leaks, on MAP cars, it dont go lean only races.
3b: air leaks on MAF , causes lean conditions, (most modes)
on a maf based engine any induction leaks too big will cause
the B1S1 sensor to loose control at idle or low speed cruise,Hot)
there are other reasons.. many.
the above is basics.
let it be said, the engine that misfires, sends a slug of oxygen
to the sensors. and causes it to mess up.
this is the bad deal with all narrow band oxy sensors...
they dont see misfire. correctly.
what we do in a shop is see if we can wake up the sensor
(no cracks found in header)
(S1 is the PRE CAT sensor , one more way to say it)
we force the EFI rich, and scan and graph the S1.
how? , well there are 2 ways.
1: is add propane gas to the induction, (air cleaner works)
2: or force fuel pressure higher, on MAF cars, we pinch the vacuum
'hose to the Fuel pressure reg, this makes it go about 10psi higher.
now you know a trick. or two.
the o2 will go rich showing that it is alive. if not , its dead.
or has horrid levels of oxygen flowing by it.
(gross misfire, burned exhaust valves, gross induction air leaks., etc)
Dec 25, 2013 |
1998 Toyota Tacoma