Help! p0128 and p0172 codes

[jdavi67]

I recently bought a 2005 gx470 with 190k miles. It runs great. However, I am chasing a couple of new codes. I had p0128 (not coming up to temp fast enough) pop up and I replaced the thermostat and it never came back. Afterwards I had the p0172 code pop up (Bank 1 too rich). I cleared it to see when it would come back and it took a day or so, but it came back. I cleaned the MAF sensor to no avail. I noticed the rpms will shift a little during idle and once I had heavy hesitation during acceleration. I restarted the car and it drove normally. Any ideas?

 

[quasi]

good chance your O2 sensors are done.