It must be OIL depotsit, from say a leaking vlave seal or bad ring....So fast forward 9 years and experiencing same problems.
First test High NOx and HC.
Replaced plugs, tested wires, replaced cap and rotor, replaced air filter, replaced cat with ca compliant model. Long term fuel trim is still reading 46%. No codes.
Second test Hi NOx Gross polluter. HC have returned to normal.
During second test started leaking coolant. Later found out it was the water pump. Could low water level cause NOx to increase?
When replaced the plugs there was some major deposits on one of the plugs. Almost enough to bridge the gap. I am thinking the spark plugs alone corrected the hi HC.
Could these deposits be caused by a leaking injector? If only one injector is leaking could this cause the O2 to read rich, causing the computer to lean out all injectors to correct the rich reading?
Long term fuel trim is being enriched 46%. The short term trim is reading -512ms at idle.
I'm at a loss any help would be appreciated.
Wouldn't oil show up as a rich condition?It must be OIL depotsit, from say a leaking vlave seal or bad ring....
oil deposit cause Hot spot in cumbustion chamber and lead to Hi NOx...