Ses light again

[Black 98 formula ws6]

Hello, the codes are Po0172 and po0175, bank 1 and bank 2, system too rich, i just replaced the both o2 sensor light goes off for about 20 miles comes back on, I had the computer tuned by frost, lid, and no cats, and exhaust. Do i need new spark plugs? I cant figure it out, im tires of wasting money on more and more 02 sensors

[Cutlass]

check for high fuel pressure or a bad MAF

[Black 98 formula ws6]

I check fuel pressure it was normal? how do you check for bad maf?

[Cutlass]

You could try swapping the MAF with someone else's. Also inspect it for blockage in the screen, make sure it isn't installed backwards (there should be an arrow showing which way the air flows through it), review data on a scan tool, and inspect the air filter for blockage.

[pajeff02]

Since it's not throwing a MAF code -- maybe just try cleaning it with some CRC MAF Cleaner. You can get it at just about any parts store. Like Cutlass said, those are the first two things to check for the DTC's you posted. Did you check your fuel pressure both at idle and under load?