Which O2 sensor gives P0420 error code??
Pit Crew
Joined: Mar 2018
Posts: 100
Likes: 30
From: Ontario
If you are able to, plug in a meter that can show live data (I have an OBD reader that can talk to an app on my phone) and have a look at your fuel trims and your MAF data. My car presented something similar, and it turned out to be a faulty MAF. I got the replacement Denso off of Rockauto, and it's been fine since then. Took me awhile to find that one, tho!
Thread Starter
Intermediate
Joined: May 2014
Posts: 323
Likes: 5
From: Florida
Here's the ECU reset procedure. Use the fuse pull method so it will be easier.
If the car doesn't stall it was not performed correctly.
https://www.clublexus.com/how-tos/a/...our-ecu-363500
Try that then report back if the CE lights up.
Did you reset the ECU as the data is indicating MIL on? If not you want to rest the ECU. So it wipes the fuel trims. It looks like it's trying to correct itself if you didn't wipe the ECU.
Here's the ECU reset procedure. Use the fuse pull method so it will be easier.
If the car doesn't stall it was not performed correctly.
https://www.clublexus.com/how-tos/a/...our-ecu-363500
Try that then report back if the CE lights up.
Here's the ECU reset procedure. Use the fuse pull method so it will be easier.
If the car doesn't stall it was not performed correctly.
https://www.clublexus.com/how-tos/a/...our-ecu-363500
Try that then report back if the CE lights up.
Hmmm..... calculated engine load >30% at idle and HPFP at 5xx psi. That all seems wrong to me. Mike, you ever see it that low?
Yeah some info is iffy now that you mentioned it. What caught my eye first was the MAF reading at idle 3.17% at idle is this a IS250? The way I see it on my phone the edges are getting trimmed not sure if it's a screen shot, or picture. It could be other issues at hand. I'm just arm chairing it.
Yeah some info is iffy now that you mentioned it. What caught my eye first was the MAF reading at idle 3.17% at idle is this a IS250? The way I see it on my phone the edges are getting trimmed not sure if it's a screen shot, or picture. It could be other issues at hand. I'm just arm chairing it.
The fuel pressure and calc load puzzle me.
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Last edited by MikeFig82; Feb 6, 2023 at 04:03 PM.
Thread Starter
Intermediate
Joined: May 2014
Posts: 323
Likes: 5
From: Florida
Just recorded my screen while driving into work. I can record again if you want me to not scroll and just stay on a certain part of the readings.
https://streamable.com/0hace6
https://streamable.com/0hace6
Pit Crew
Joined: Mar 2018
Posts: 100
Likes: 30
From: Ontario
I tested my 250 when my MAF was giving me grief; at 750RPM, it should be 2.5g/sec, or close to it. If that figure is off, the MAF is your primary suspect.
Thread Starter
Intermediate
Joined: May 2014
Posts: 323
Likes: 5
From: Florida
Any input on this?? It's updated after I replaced B1S1 and B1S2.
Just recorded my screen while driving into work. I can record again if you want me to not scroll and just stay on a certain part of the readings.
https://streamable.com/0hace6
https://streamable.com/0hace6
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binkyrules
GX - 1st Gen (2003-2009)
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Mar 12, 2021 06:54 AM