Hello everybody, nice forum. Just wondering if anybody could give me a little direction. I've got a 2000 F150 with a 4.2L V6 and she's started acting up on me. I borrowed a code reader and it's showing codes P1120, P122, P1121 which are all TPS related. I've also got P136, P141, P156, P161 which are O2 sensor related (know what's causing that, catliletic converter was removed years ago and the O2 sensors were just unplugged and left open ). Also got P171 and P174 which are system too lean (both banks).
I guess the main question is about the TPS codes, is there a common problem area on these trucks that bring up the codes or does the TPS just fail occasionally? I believe the TPS is causing the transmission to act up now, when I drive the truck on the highway if I push the throttle to the floor the transmission will stay in overdrive but if I back down to about half throttle almost always it will shift to drive. Sometimes it will shift to OD at about 50km/h and not have enough power to accelerate, I have to shift down manually to go. Other times if the conditions are just right on cruise it will shift back and forth between drive and overdrive up to ten times or more per minute. Another thing that happens is if I drive during snowy conditions sometimes it will not shift higher than second gear. One other thing; when I start the engine almost every time now it will rev to about two thousand RPM for about a minute then slowly come down to an idle, or rarely it will start to either flood or lean out (not are) and almost stall.
Another question; how does the O2 sensors being disconnected affect the vehicle, anybody know?
It's a very good truck, I've been driving it for the last 150000km (it has 353000km on it now) and it's only left me walking twice (once was a flat tire so technically once ) And last time was last month when I was ploughing through snow drifts during the last storm which ran the fan belt off and a poor old battery couldn't hold enough reserve charge to quite get me that last ten miles home (quit within the last mile ).
Sorry about the story telling , want to cover all symtoms .
Thanks.

 

The 0/2 sensors tell the computer how to adjust for almost everything in the powertrain.Initially,they control the amount of fuel being injected into the engine.
Having the Cat,s removed,and 0/2 sensors disconnected,Im surprised it runs at all.
My suggestion is to put the converters back in,and install new 0/2 sensors to begin with...replace the plugs,and go from there.

 

Well the truck probably has 200000km on it without the converters and this just started a couple months ago. Plugs have 50000km on them, fires good on all six.

 

As you wish,I just know that when you alter these newer vehicles from factory equipment,sooner or later its gonna come back to bite you.
Perhaps someone else will give you better advice.Good luck!

 

It is possible, thanks.