Which codes should I pay attention to? Read codes or Test Codes with green plug connected? I get p0170 p0302 p0303 in Read and I get p0500 p1101 in Test mode?
Have you googled each individual code? That's the best place to start.
P0302 and P0303 are cylinder misfire codes, #2 and #3. How old the spark plug and wires. Replace those first. Check your air filter and clean MAF.
thanks for the answers. Have replaced plugs, wires, coils. Engine has good compression (225). But was interested in the priority of trouble shooting a problem. Should I use the read codes as a priority or the test codes? P0500 refers to a VSS problem and p1101 refers to a neutral safety switch issue. Misfire codes I can't figure out. Can't find air leakes, fuel pressure good, Car dies when going up hills and runs rough so I am starting to feel it is the CAT causing this problem. Any opinions? Sorry for my late response.
"Read" codes first.
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