Will disconecting battery reflash ECU?

[J Browning]

I bought one of the SCT performance CHIPS a few years ago but ever since I have had an engine knocking problem between 2-3k when going up hills or towing something. On hots days its worse. temps over 80 degrees. I have ran all types of gas and no improvement. Going through some of the mountain passes here in AZ I just listen wondering if this is the day it blows a hole in the side of the block. I had an old jeep and the same noise blew a hole through the engine wall and shattered a rod and a piston because of bad timing.



Anyways I pulled the CHIP about a year ago, took it to the dealer for a diagnostic and they said it was more than likely my MAF sensor or the K&N filter, suggesting I switch back to the stock airbox. I replaced the MAF sensor and still have the same problem. Now I'm looking to buying an airbox.



When disconnecting the battery does it reflash the ECU back to stock? I think that is were I should start but I'm assuming only a dealer can do that.



That CHIP cost $300, I could barely sell it for $100, and ever since I have had problems!



Any ideas?



Thanks, Jason

 

[TrainTrac]

I'm not sure I understand you... Is the chip still in the ST, or did you actually sell it? If it's not in the vehicle, then you're running on your stock ECU. You can disconnect the battery for about 30 minutes and this will dump the ECU, forcing it to relearn when you start it back up. Other than that, I'm not sure about your problem.

 

[J Browning]

No, the CHIP is gone. I let it sit over night with the battery disconnected a couple times in the last year so it could relearn everything but still had the same knocking issues. Definitely not the timing chain rattle.



I was thinking that the CHIP changed the parameters of the ECU permanently. And that it would have to be reflashed to have everything back to normal.



To bad there is no way to retard the timing manually.



If its not the MAF, and the ECU is back to its original state then I'm clueless besides the airbox.



No CEL at this time. I had a CEL for EVAP something or other one time but it went away on its own.



J~

 

[David Ponder]

Is this a knocking sound or more like a rattling sound?

Perhaps the Tensioner issue in the 4.0?



(My 01 had that issue and it rattled under a load, like spark knock)

 

[EddieS'04]

If it is a spark knock. It might be the crank sensor at the hamonic balancer is bad or bent out of position. It could be the ECU is going bad. Or if you have a flex fuel. The knock sensor could be the problem.