Patent ID: 9534984
Date: 2017-01-03
CPC Classifications: F02B,F02D,F02P,G01M

Claim:
1. A method for an engine, comprising: inferring spark plug fouling due to accumulation of fuel additive based on a combination of two or more of a change in an adaptive knock term, an engine pre-ignition rate, an engine misfire rate, an exhaust oxygen sensor degradation rate, and exhaust catalyst degradation rate over a vehicle drive cycle in response to the inferring, indicating spark plug fouling due to accumulation of fuel additive wherein the spark plug is coupled to a cylinder, in response to the indication of spark plug fouling due to accumulation of fuel additive, decreasing an engine load, and disabling fuel while maintaining spark ignition timing for the cylinder for a threshold duration, the threshold duration including a threshold number of combustion cycles.