kalo93406

Hi I did finally get this work done... I found a local shop that someone recommended and convinced them that I wanted to get the two knock sensers myself in case they were not bad then I could return them. They quoted 4 hours labor I think. I got the kock sensors from Rockauto.com for $257.07 total.. a really good deal i think. The service guy got the electrical pigtail.. he told me about 65.. but in the end it was only $35 Also the gasket was only $11.99... I ended up paying for 3.5 hours labor.. (he said the book says 4.5, but he had chaged me for 1 hr already so gave me some credit) So the total was $257 + $35 + $12 + $283 = $587 Everything seems to be ok.. no engine light yet and shifting is good.. Service tech said it was a bit of a pain to do. He also said the knock sensors I got were of good quality. (i think they were Standard Auto)

I just had my car looked at today. They said they can't check all of the wiring to the knock sensors because the intake manifold is in the way, can't disconnect the pigtails from the knock sensors. So the wiring can't be checked until the intake is off. This repair shop said 90% of the problems with knock sensors have been the wiring harness. I've decided to have them do the work. Will have them order the wiring harness and intake gaskets, but I will bring in the two knock sensors. If only the wiring harness proves to be bad then I'll return the two knock sensors. I think the wiring has one main plug then pigtails to two separate plugs going to each knock sensor. Price about $65.00 for the wiring harness. They say it is 4 hours labor for the job. This web site below had the lowest price ($143 -partsamerica.com) for knock sensors of about 4 web sites I looked at. They seem to be associated with several autoparts chains including Kragen, so I think I will check prices at the local Kragen Auto Parts. Local Autozone quoted $190 each. http://www.partsamerica.com/ProductList.as...=Knock%20Sensor Will post again if I get the work done soon.

Yes I wish i had done a little research on the Mass Airflow Sensor... I'm sure my "old" one is good if i had learned about cleaning it. Very easy to get to also. My "knock" was resolved by the MAF change out. So I'm wondering if these Knock Sensors really are bad or not. The dealer said it was an "open" circuit for the knock sensor. They seemed to think is was a wiring issue. My RX300 runs good, but has the downshift problem and doesn't easily go into the last gear, so has high revs if try and go over 55-60 mph. I hate to have the knock sensors replaced if they really aren't bad. I only had 48k on my lexus, but was over 4 years, so they wouldn't cover it under warranty. :( Is there anyone who can help me with the location of the wiring for the knock sensors?

I had pinging going up hills and an engine check light. They changed the MAF sensor and the pinging went away, but then i got another engine light.. this time they say Knock Sensor Open code. They seemed to want to check the wiring more than replace the knock sensors. They also said knock sensors are NOT likely to fail. I didn't have time to have them check the wiring, so still have the problem. Will be trying to do it this weekend. One other tidbit is there were some paw prints under the hood, so some varmit was under there and i suppose it is possible that it chewed through some wiring. Can anyone help me with tracing the wiring for the knock sensors? Thanks! Roger

Chelo.... Did you get the problem fixed??? I have the same problem. First they changed the MAF and the 2000 RX300 ran better but then another engine light.. this time they say KNOCK SENSOR open code. I didn't have time have them look at it.. so still have the problem.. please please post a follow up.

Thanks for continued input and patience. MAF was replaced last night and nothing changed. Can't see a temp difference with laser gun on right cylinders either. Was told today that Cat. Converts. all need replacement, however cats. are now only $150ea. I said fine, do it, must have car tonight for long business trip tomorrow a.m. in Toronto. Does this sound right? ← MichiganRX... did you ever get this fixed??? I have a knock sensor open code and my car goes in to limp mode and won't shift into high gear.. I'm wondering if you have a knock sensor problem.. I also had my MAF replaced. now it runs smoother , but still have the high gear problem with the check engine light... thanks.. Roger

do you still have the diagrams to email? thanks R kalo93406@yahoo.com