is resetting ecu necessary?

[SteveU]

I installed ngk iridium plugs about 1700 mi ago replacing bosch platinums. idle & performance seem to be improved but mileage is down slightly. Car calls for .035 gap, I installed the iridium plugs at the .042 factory gap since they don't recommend gapping them. Would resetting the ecu help with mileage or even be necessary or does the ecu gradually adjust to new plugs over time? If it does adjust itself, how long does this process take? The car is a 95 Geo Metro 1.0L 4ycl.
Thanks,
Steve

 

[drive it forever]

You have the wrong plugs installed. The ecu isint designed to cope with a wrong spark plug and/or plug gap. You might have a weaker spark with the larger gap.

[ March 03, 2005, 04:03 AM: Message edited by: drive it forever ]

 

[BlazerLT]

Gap them to the specified .035

 

[55Test]

You kinda threw your money away on those Iridium's. Get yourself a set of NGK Vpower plugs, they seem to work the best in that little 3 banger. I had a set in my Geo and I never had trouble with 'em. Check your timing after you're done installing the plugs. I ran my 93 Metro at a hair over 7 degrees, gave it a bit more pep and I believe may have increased fuel mileage as well. Man, I need another one of those cars..

 

[TheLoneRanger]

Steve, if your Geo is OBD II, it will compensate for tune-up changes during approximately 70 start cycles. If OBD I, it dosen't matter. 1995 was a transition year, but I suspect yours is OBD I (with spark gap of .035).

 

[ebaker]

Changing to Iridium plugs shouldn't cause any problems, as long as the heat range is correct.

 

[SteveU]

Yes, these are the recommended plugs & it starts easy & runs good. It started being colder on average right around the time I installed them so running on the choke longer could be the reason the mileage is down. Hopefully it starts warming up soon so I can get a better idea. What is the difference between obd1 & obd2?