Owelly

I'm going to leave one of the sensor circuits open and see if the same faults ping at the same time.....

The confusing bit is that without the loom plugged into the ECU, the fault doesn't ping immediately. It would be good to know the 'pending' and 'fault' parameters because at the moment, it all seems a bit random!! The originals and my replacement sensors all show 1.7vA/C ay 4kHz with the engine running. The other thing to mention is the ignition timing. It's doing as I'd expect and adjusting with the load. If there was a geniune knock, I'd expect to see the timing advancing to counteract the knock.

Thanks for the reply. I did scope at the ECU end of the loom and it checked out fine but as it wasn't 'real' (ie not being driven to ping fault) it didn't prove much. I think the next step is to do a continuity check between the ECU and engine bay and go for a drive.

Greetings. I've done the usual searching but not found anything specific to my problem so here goes: I bought a 2000 RX300 that had sat for two years due to needing welding and rear brakes. I did all that but the EML was on. It showed dozens of faults which were probably caused by a flat battery. Once reset, the car had a very high tickover and the EML came back on showing the P0325 and P0330. Cleaning the AFM sorted the tickover problem but the P0325/P0330 still popped up. These numbers are obviously the two knock sensors and it's very unlikely that both have failed at the same time, but as I don't know the history of the car, they could have been on for a long time before it was parked up. Not having the time (or wanting the expense) to replace both sensors, I ran the car with a scope attached to the knock inputs at the ECU and they both seemed to be steady at 4k but as the fault was intermittent, it wasn't easy to replicate the fault without driving with the scope attached!! Anyhoo....I decided to bypass the two knock sensors and join the two wires under the bonnet nd fit another knock sensor on a bracket on top of the gearbox where it was easy to reach. It's made no difference to the EML! It still comes on showing the same fault codes. It does the same with no sensors attached and the loom unplugged at the ECU?! Any suggestions as the car needs new tyres and exhaust which it won't get if I can't sort out the knok problem! I may just cut my losses and weigh it in!! Cheers guys.

I put fresh fuel in as it was empty. I've swapped the battery with one off my other car. I'll fix the exhaust and see if that helps the poor running then look to do a full service. I've used SGS before so I'll try them if I can find a cheaper option. Thanks for the help guys.

I drove it about for 20 minutes but not over 10 mph and just around some moorland so possibly not enough to ping any faults but my reader didn't show any pending faults, which it wouldn't if it was fighting with high O2 at one of the sensors....

Yesterday I collected my first Lexus. A 2000 RX300 that was parked up 6 months ago due to a loss of power, busted exhaust and no parking brake. I blew up the tyres, charged the battery but it refused to start. My OBD diagnosis showed many many faults due to the flat battery so I cleared them all. It then started first click and ticked over fine however it would not rev off the pedal. If you floored it, it would die. Feathering the throttle around halfway would get it revving. I unplugged the AFM and it pinged the MIL and caused it to not tick-over. I plugged it back in and reset the DTC and the MIL extinguished. This could be because of the exhaust as it seems to be leaking between the O2 sensors. Or is there any other things to look at? The other problem was the parking brake. The brake shoes had no meat left on them so had welded themselves to the drum. The bolts holding the caliper carriers have been rounded so the only way to get the drums off, was to smash them off!!! Thankfully they're really cheap and new discs, pads and shoes are already on their way. Finally, tailgate lift assist struts. Scrapyard or new? Thanks in advance.

Thanks for the welcome. I collected the RX300 yesterday so I now have a long list of quezzies!!!

Greetings from a sunny Whitby!! New to Lexus ownership and I've jumped in at the deep end with a 'bangernomics' RX300....... It's an MoT failure as the handbrake isn't very good and it is low on power. I still have to have a good look around it and no doubt I'll be full of questions soon..... Cheers!!