I just did plugs wires and o2 sensors and now I have a bad miss and vibration. I checked all the wires to see if they are on tightly and so far they are. I then replaced the coil and same problem. Another strange thing is that at high rpm's, the tach jumps all over the place. I went with autolite 104's this time because I needed a little colder plug and Im tired of all those damn bosch plugs. any Ideas?


thanks in advance

Chris

 

Are they all secure in the opti and did you double check the order? Did something else get disconnected in the process?Check codes for other problems.

 

Sounds to me like the 4 pin connector at the opti is a problem. The PCM gets the signal from the optical encoders in the opti and then the PCM sends the signal to the tachometer based on the signal from the opti. Unless you disconnected the harness at the PCM, the problem has to be at the opti connector. Check it for bent pins or corroded connections. You may want to ohm out the wires from opti to PCM to be sure you have good continuity. BE SURE IT IS DISCONNECTED from the PCM and the opti before you ohm it out.

BTW why would you go with cooler plugs, are you racing? If you don't have a detonation problem, stay with the recommended plugs especially if you do blvd cruising.