Misfire (M271) O2 Upstream Sensor reads 2 Volts - Is this a sign it is about to fail
#1
Misfire (M271) O2 Upstream Sensor reads 2 Volts - Is this a sign it is about to fail
I have a C180K 2006 with over 100,000 miles on it
After taking off the cylinder head and putting the engine back together after replacing the cam adjusters and gears due to slipping 3 teeth i now have an engine misfire when hot.
I am thinking of taking the o2 sensor out and cleaning it with electrical cleaner to see if it makes a difference
Any ideas anyone?
Thanks
After taking off the cylinder head and putting the engine back together after replacing the cam adjusters and gears due to slipping 3 teeth i now have an engine misfire when hot.
- Engine runs smooth on idle and drives fine while cold
- One engine gets up to full temps it develops a misfire and throws engine light code for cylinder 4 misfire. It has also shown a misfire on cylinder 1
- I have changed over the coil packs and plugs to see if misfire follows them but it doesn't
- If i leave the engine to cool and restart then the engine runs smooth again until it gets up to full temp and then misfires again
- The Short term fuel trim reads around 2.2 and Long Term fuel trim reads a constant 0.8
- The O2 B1 S1 sensor reads 1.5v and goes upto 2.2v when the misfire begins
- I have sprayed engine start around the intake to see if misfire disappears but it doesn't change the engine note at all so i don't think it is an air leak near the intake manifold or air b
I am thinking of taking the o2 sensor out and cleaning it with electrical cleaner to see if it makes a difference
Any ideas anyone?
Thanks
#4
I have a C180K 2006 with over 100,000 miles on it
After taking off the cylinder head and putting the engine back together after replacing the cam adjusters and gears due to slipping 3 teeth i now have an engine misfire when hot.
I am thinking of taking the o2 sensor out and cleaning it with electrical cleaner to see if it makes a difference
Any ideas anyone?
Thanks
After taking off the cylinder head and putting the engine back together after replacing the cam adjusters and gears due to slipping 3 teeth i now have an engine misfire when hot.
- Engine runs smooth on idle and drives fine while cold
- One engine gets up to full temps it develops a misfire and throws engine light code for cylinder 4 misfire. It has also shown a misfire on cylinder 1
- I have changed over the coil packs and plugs to see if misfire follows them but it doesn't
- If i leave the engine to cool and restart then the engine runs smooth again until it gets up to full temp and then misfires again
- The Short term fuel trim reads around 2.2 and Long Term fuel trim reads a constant 0.8
- The O2 B1 S1 sensor reads 1.5v and goes upto 2.2v when the misfire begins
- I have sprayed engine start around the intake to see if misfire disappears but it doesn't change the engine note at all so i don't think it is an air leak near the intake manifold or air b
I am thinking of taking the o2 sensor out and cleaning it with electrical cleaner to see if it makes a difference
Any ideas anyone?
Thanks