156 JTS - lack of power when warm
I have a 2003 156 JTS with 30k miles on it and I have a bit of an issue.
When I start the engine first time and drive it for around 5 minutes while its stil cold and warming up, the engine feels good - it feels 'punchy' and 'lively' like it realy has 165 hp, but as soon as the engine warms up to a full operating temperature (usualy after 10 - 15 min) the engine feels like it gets lazy and that punchines is gone.
When I floor it the revs stil rise towards the redline normaly but it just feels 'flat', this is especially noticable on full acceleration in 2nd gear. It feels like it lost 30hp for some reason.
Now recently I took it to dealer to get it examined cause I was getting 'motor control failure' warnings that would usually happen when accelerating hard and the engine would stutter for a while like it had a misfire but then everything would go back to normal and the warning would go off after 5-10 seconds.
The dealer got a code for a misfire in cylinder number 4 so I will be changing the coil pack on it as well as the spark plugs. But he has also got the codes p0135 and p0155 which both relate to O2 Sensor Heater Circuit Malfunction on sensor 1.
Could a faulty O2 sensor cause a loss of power when the engine is warm?