put my 88 toyota picup i the shop cause im getting a code for my knock sensor. the guy at the shop changed it and the code still shows up. he couldnt figure it out and said to take it to an auto electric shop but i figured id stop by here and see if anyone could give me a few things to check first. thanks for the help yet again.

What type of code are you getting, Knock sensor or knock sensor wire?

Did your mechanic check the wire for damage?

Did your mechanic replace the knock sensor with the right year sensor, or just one he had laying around? KS's differ from model run to model run, the pre '89 sensor is different than the '89-'91 which is different from the '92-'95 sensor. Before taking it to another shop, I would make sure that the KS used was the correct one. I would take it back to the store that supplied it and get another one, or to get a used from from the same year(or era) as your rig. The dealer can test your original KS(if your mech still has it), should/might be free, my dealer service center didn't charge me, though others may charge for the test.

If teh KS comes loose it can also trigger the code. When searching for a solution to my KS wire code, I came across a post where the guy had had the code for 3yrs, and all his problem was, was that the KS had come loose in the block.

he pulled a KS from the same year model truck that he new worked and was the correct one. the code is for the KS itself.

Check the continuity of the wires from the KS back to the ECU, both the signal wire and the grounded sheath as well. ECU pinouts on the page below:

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml#Troubleshooting

Were the stored codes cleared before firing up the truck with the replacement knock sensor?

the diagnostic was cleared and it came back on, but now it goes off when i drive and at a little while of idle it will come on then go off when i drive again. wire problem im guessing. gonna look it over tomorrow.