P0420 and P0303 Code CEL Help
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Super Member
Joined: Aug 2004
Posts: 791
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
P0420 and P0303 Code CEL Help
I've been having a constant loss of power with my car lately. It seems that when I floor the the gas and have the engine rev to the redline the car loses power and does not shift correctly. There are delays in every shift and sometimes the car even gets stuck at a high rpm but has very little power and does not downshift.
I had the entire wiring harness replaced last November for a terrible engine rattle on startup and also the cam sensor oil dripping in the wiring harness. I am wondering if it is my cat that is toast (p0420) because of the wiring harness issue I had for many years causing my engine to dump or not give enough fuel into the injectors?
And also could a bad cat give off a misfire on a cylinder (p0303)? I ask because when my CEL went on I redlined the car and it got stuck at around 6,000 rpm then gave the CEL.
I had the entire wiring harness replaced last November for a terrible engine rattle on startup and also the cam sensor oil dripping in the wiring harness. I am wondering if it is my cat that is toast (p0420) because of the wiring harness issue I had for many years causing my engine to dump or not give enough fuel into the injectors?
And also could a bad cat give off a misfire on a cylinder (p0303)? I ask because when my CEL went on I redlined the car and it got stuck at around 6,000 rpm then gave the CEL.
