Engine Check Light

[cruzer]

Cruising at 40mph--locked in overdrive--smooth road--Bingo--lite came on---10 miles later I had checked oil pressure --OK--water temp--OK--engine running smoothly. 10 miles later, under the hood--saw that intake duct had slipped back---small crack visible---repositioned and tightened. Engine ran smoothly . 40 miles later, cruising at 40, in over drive--rpm 1,000--going up steep grade--got very mild ping--could not duplicate. Now, the questions. What code would a leaky intake throw --and could the computer correcting to the new intake flow cause the ping ????? Will be at dealer on Monday for scheduled maint--just want to have some info before I go in. :help::help:. Maury

[Pat]

OK, reseting the intake tube seemed to clear the CEL, or did it? May return after a driving cycle. I gather you don't have an XCal II or you would have read the code(s). The pinging is a sign of too little octane, or poor gas, or even a hardware problem causing a lean condition. You really need to read the codes, otherwise we are just guessing.

The computer adjusts AF ratio on each stroke of each cylinder, if a condition is just momentary then there may not be a code but if the condition exceeds the computers established parameters a CEl would appear. The dealer should be able to read codes, past, present and pending, but because you have a tune some things will appear abnormal like CAT logic turned off. So be aware of what they report may be normal for your revised program.

Maury, please let us know what the dealer says, so we can add it to our data base.

Regards,

[fastblackmerc]

I'd remove the negative battery cable for 30 minutes, then reconnect it. It should reset the computer.

[cruzer]

I did the battery ground for 30 minutes--reconnected--started engine--check engine light was "out"--used the procedure in the manual to reset the idle---took the car out for a test drive---WOT--"D"---burned rubber on 1-2 shift at 50--chirped on 2-3 shift at 92--smooth all the way--no hesitation or ping. Now the dealer doesn't get a chance to mess with my DR tune :D Thanks again---the fun is back !!!!! Maury

[Pat]

So, the mysterious CEL is gone, the ping is gone, all because the computer was reset.

Well, that's good to know. Atta boy, fastblackmerc.

Regards