I've noticed what seems like a slight misfire whenever the van is climbing a slight grade at freeway speeds. If the cruise is on, it downshifts readily. I don't recall it downshifting quite so frequently in the past. Once downshifted the misfire is gone. This is the only time it does it, I can't recreate the problem on overpasses in town or highway driving at lower speeds. I didn't think it was to much of a problem until I checked the gas mileage over several fillups. Used to average 32mpg, now it's 23 (Canadian). The van is a 98 with 100000 Kms. A few months ago I changed the sparkplugs,pcv valve, air and fuel filters. I checked the 3 front plugs (the easy ones), they looked good. Tailpipe doesn't have carbon in it and there is no check engine light on. If anyone can offer any advice I would appreciate it. Thanks Matt
- posted
19 years ago