I just changed the spark plugs in my rodeo yesterday - I bought autolite dbl platinums. This morning I have a check engine light on - should I have bought a different brand?????

Yes, you should've used the Denso brand. The original number should be in your owner's manual. Some came factory with Champions (mine did), but the Denso's seem to work best. That seems to be the consensus around here, anyway.

very well - thanks so much

I've also heard of NGK iridium plugs working. Personally I prefer denso, they've always performed way better then any other plug for me.

The reason for certain plugs is that the ignition system on yours uses the plugs as a sensor. If you dont use the right plugs it will read wrong and you will get a misfire code.