Check engine light stays how to get it out

the code will tell you where to look

Maybe get a techy to get into reset computer to tell it these things have been done. When ever I replace brake pads have to reset computer because it says ABS, Trac is outa wack when they are not

you need to have codes pulled and go from there... or you can waste a load of money by replacing every sensor on it

The check engine light will come on when the ECM detects knock, it will only stay on if excessive knock is detected. I would replace the fuel filter and check your fuel pressure.
Could also be a bad knock sensor as the ECM will also advance the timing to make the engine knock. If on knock is detected when the ECM is doing this it will light the check engine light.

To review, the check engine light will stay on until the problem is fixed and the code or codes are erased. And if the O2 sensor is disconnected the light will stay on for sure.
Do you have the trouble codes stored in the computer ?
FYI - the cylinders should have over 100psi of compression.

If the check engine light stayed off then that means that those errors are not present at this time. It is not un common to have intermittent faults but I would not preced any further until the light comes back on. Then re-scan the code see which are to begin diagnostics.

Have you tried to disconnect the battery for a while, since you changed the Oxygen sensor? The light won't just go out by itself, even though you most likely fixed it. If you clear the code, and it comes back, then you need to dig deeper!

something like O2 sensor will cause the check engine light stay on, not too worries,or you may take it to dealer did a service.(the light may stay on on that year model even after service.)

First did you clear all the fault codes after your repairs? The reason I ask is po131 is bank one oxygen sensor, po174 is engine lean from faulty oxygen sensor, and po171 is engine lean condition, possibly from vacuum leak (intake manifold gasket?), pcv valve,etc. To check for vacuum leak at intake, start engine and gently spray starting fluid around intake gasket. If rpm raise slightly while doing this then there is a vacuum leak(stay away from air filter intake and housing though), and the gasket will need to be replaced again.

there are 3 one on each side of eng. on the Y pipe one behind the cat. convertor. not to hard change