this is a rebuilt 22re with LCE head. its been in the truck about three years at maybe 25000miles.

started giving me a code 25 [engine lean] and 52 [knock sensor] plus idling very rough. runs good at wide open throttle, down on power alittle. mileage is very bad, not even getting 200miles per tank.

i did a basic tune up: plugs wires cap/rotor, checked the timing [seems to be jumping around] and a compresson check {185, 185, 145, 185}, i added a tbs of oil to the low cylinder and it jumped up to 180.
thought it might be o2 sensor, but the output looks ok: jumps between .3-.4 volts but all the way down to .19 every now and then, checked it at the sensor and at the diagnostics plug, same reading.

i'm not stoked on the low compresson on the #3. i checked for vaccume leaks with propane and starter fluid but found none, vaccume at idle is about 16lbs. it has always started on the first crank, but now when warmed up i have to pump the gas some to get it to fire. fuel filter was replaced when i built the engine. plugs looked ok, maybe alittle white [hot], except for the #3.

any ideas? i'm not sure where to look next. i wouldn't think the low compresson on the #3 would cause the engine to lean out.

 

code 52 will cause your timing to be retarded but usually will make you run rich hence the horrible economy. before tryign to replace the KS (240-300 bucks new) just try replacing the KS pigtail wire its a 12 inch wire that plugs into the KS and the harness, they are known to fail because of where the wire sits, code 52 can be a bitch to deal with sometimes, im currently dealing with it now. 82219-89103 is toyota part number for the pig tail you will need to replace. if you still get the code after replacing pigtail run a coaxial cable from your ecu to the pigtail and try running it and seeing if you still get code 52. if you don't then you know its the wire and will need to rerun the wire. if you need any more information on it send me a pm i have been reading for days on possible solutions to code 52