Don; <BR>Lets be careful here. When raw(read unburnt) fuel goes through the motor and into the exhaust system - there are some dangers.<BR>1. the unburnt fuel can dilute the engine oil and result in loss of the lubrication qualities that the oil has. (lifter noise??)<BR>2. Unburnt fuel will overheat the cat. and DESTROY IT in short order.<P>Now - is this something that has been very subtle for some time and now is noticeable enough so that it becomes a concern ??.<P>Some things that no-one has brought up yet and are VERY IMPORTANT.<P>1. The coolant temp sensor that the engine control computer uses to sense engine temp.<P>2. The throttle position sensor that gives the computer an indication of load on the engine as well as throttle opening and the rate of throttle movement.<P>These two sensors ARE critical to operation of the motor and also have the highest failure rate because of a constant temp change/ and constant throttle un-put changes.<P>Check out these suckers!!!!!!!!! I have repaired the TPS sensor - when I checked on that one it was $186.00 USD. my cost!!<BR>The coolant sensor should only be $ 20.00 to 40.00 USD or perhaps less.<P>Also be aware of constantly using a cleaner in the gas will contaminate the engine oil.<BR>Let me know what you find.<BR>Good luck<BR>Kary