My 1996 lexus lx450 shows knock sensor code PO 330 PO 325. I have had this vehicle at several shops including lexus however they can't determine the problem. Vehicle had couple minor air leaks which I fixed. Engine works perfect, however engine light is still on. Any suggestions?

No power to fuel system whole from fuel pump to distributor

Diagnostic computer says cannot ocommunicate with car


But comes back on after 2 or 3 engine cranks.

The ECU was checked and is working properly. Where do I look next?

my car begins a major vibration, accompanied by power loss, after 15 min driving at 65 mph. Pull off freeway and drive on surface streets, problem disappears. Tires/balancing ok, shocks replaced, tuneup done, brakes and rotors checked.

What else?

I have a P0401 code up solid. I have changed the EGR valve and modulator. I suspect the EGR temperature sensor is bad, but I do not want to spend $175 to find out. Can I measure the detector with a Meter to see if it is bad? What should I expect to see if it is still working? "

I have failed my emissions now 4 times. 1st time battery was dead from sitting, replaced battery then check engine light came on it failed stating needed to wait for computer to reset & to drive for 2 weeks. Went back 2 weeks later it failed stating O2 censor, replaced it went back then it stated the computer needed to reset again,. drove it for 2 weeks now its showing the lower O2 Censor... What the hell? What do I do?Why is this showing up now?