Hi guys,
I have a 02 Trailblazer 4.2L, I6 and I have had trouble lately since a tune up. I had purchased a set of ignition coils on ebay (bad idea), and a set of NGK iridium plugs. I cleaned my throttle body, gapped the plugs according to spec and swapped everything in. The car ran with exceptional performance for one day. On the second day, it developed a misfire on the way home. I pulled the coils and plugs and checked 'em. The plugs were fine but a shop told me that #4 had a misfire. I swapped #4 for a new coil and it ran fine for a month. Then another coil dropped so I put all the old coils back in and it runs ok. I went out to buy a OBDII scanner so I can check my own codes and I plugged it into the under dash connector but nothing happened when I put the key in the on position. After a number of tries, I'd remembered that the guy at the shop had the same problem. He instead connected his diagnostic machine from under the hood. I looked under there but I guess I'm missing something.
Is there another data link connection under the hood like the one under the dash so I can retrieve codes with my scanner or is it a different kind of connector?
I really would appreciate a point in the right direction. I love my TB but I'm a working man. So like everyone else, I gotta have the car running Monday to Friday without fail. Weekends is all I have for solving transportation problems and enjoying my machines.
Sorry if this is a topic that was discussed already but I searched and couldn't find it.
Thanks
I have a 02 Trailblazer 4.2L, I6 and I have had trouble lately since a tune up. I had purchased a set of ignition coils on ebay (bad idea), and a set of NGK iridium plugs. I cleaned my throttle body, gapped the plugs according to spec and swapped everything in. The car ran with exceptional performance for one day. On the second day, it developed a misfire on the way home. I pulled the coils and plugs and checked 'em. The plugs were fine but a shop told me that #4 had a misfire. I swapped #4 for a new coil and it ran fine for a month. Then another coil dropped so I put all the old coils back in and it runs ok. I went out to buy a OBDII scanner so I can check my own codes and I plugged it into the under dash connector but nothing happened when I put the key in the on position. After a number of tries, I'd remembered that the guy at the shop had the same problem. He instead connected his diagnostic machine from under the hood. I looked under there but I guess I'm missing something.
Is there another data link connection under the hood like the one under the dash so I can retrieve codes with my scanner or is it a different kind of connector?
I really would appreciate a point in the right direction. I love my TB but I'm a working man. So like everyone else, I gotta have the car running Monday to Friday without fail. Weekends is all I have for solving transportation problems and enjoying my machines.
Sorry if this is a topic that was discussed already but I searched and couldn't find it.
Thanks