Gmachine

Top left is engine RPM, MAF g/s 45MPH downhill. Bottom left calculated fuel consumption based on MAF & coolant temp





Same as before





Same, but with a slight uphill

fastnoypi

what units is the RPM/MAF digital reading in? it would be helpful if it were in volts or g/s. I would also suspect something going on with your MAF. If you haven't tried already, clean the maf sensor wire with CRC maf or electronics spray. A bit of oil or grime can throw it off.

Gmachine

Replaced both downstream O2's & it's good! I updated the first post to reflect my journey. Thanks for everyone's help. Glad I didn't pay $2000 for new cats!

fastnoypi

Glad you found the culprit and problem solved!

pluciorx

Hi I'm having exactly the same issue with both the same codes (but on RX300 ) , which part numbers did you use for the o2 sensors which fixed the issues ? I'm struggling to find which ones are those and where they are located.

pluciorx

Hi again do you remember maybe what are the part numbers for the intake manifold's the old and new designs ?
I found 17109-20130 and 1710-920100 for
as well what was the part no for downstream o2 sensors ?

Gmachine

Sorry, I haven't been on here in a while. I just bought the plug & play O2 sensors, Denso brand, of Amazon. Don't use the spice in ones. They didn't work on mine & have caused me a TON of agrivation!