TPS problems

hey everyone, yesterday i was merging onto the highway applied about 50-60% throttle to attain highway speeds, as soon as i got to cruising speed the cel came on and if i touched the gas no more than 5% it would immediately downshift to second and skip 3rd. scanned the codes and up came p0121 and p1121 which are both codes for tps. didn't get a chance to use a volt meter on the harness but i tried to replace the sensor with one from my 97 lss that had less km on it. i figured id give it a shot. cleared the code and hooked up the sensor as soon as the car was on the codes came back immediately, worse then before! tried to clear them again and the light goes off for a half second then pop's back on. put the old sensor on it and the light has stayed off for a couple hours now given i have been very very light on the throttle could this mean 2 faulty sensors? that seems very unlikely especially because i never had an issue on my lss. is there year specific differences that would cause the light to come on from the 97 sensor compared to the 98 sensor?

i really need these codes gone as i have to do emissions testing by monday or my temp stickers will run out then i cant drive the car its also been throwing the rear 02 code every 150km so i bought a new one that's going in tommorow.

any help is greatly appreciated!!

Do yourself a favor and check the vacuum lines going to and from the MAP sensor on the back of the engine. Believe it or not, a bad MAP signal will cause the TPS readings to be off under a load. The EGR, MAP, and TP sensors all share the same 5-volt reference (Gray wire).

Check for dry/cracked vacuum hoses and plastic fittings. It's also possible that the MAP sensor just could be bad. Can you monitor sensor readings somehow (scantool)?

i've been using my aeroforce,
and now that you mention it some of the vacuum wires look pretty dry rotted im going to go check everything out right now will report back in a few !

can't believe it the vacuum hose going to the map wasnt even plugged in !!! i just replaced it with a nice new section of rubber hopefully that solves the issue !!! thank you sir         

I hope it fixes your issue too. You're very welcome.

While you are "at it" I'd recommend replacing all the vacuum lines and fittings. This generation Riv really doesn't have that many, and after 15ish years, it's probably time.

I just replaced all of mine, took about an hour and I was taking my sweet time.

definitely going to replace all of them this weekend, I have a ton of extra vacuum tees and fittings hanging around. I have a bunch of maintenance stuff i have to throw in new plugs and wires, fuel filter, pcv valve, thermostat etc should be running excellent by sunday morning!