Ok l try to help people on this sight well now l need a little help working on a toyota lpg truck with 4y engine problem is truck runs rich 02senser is at almost 1volt in neutral will not change in closed loop untill truck is put in gear than 02 will switch rich lean no vacuum leaks runs good lp g converter was replaced fuel injector was replaced throttle body cleaned major tune up. Can't tell why the o2 is not switching in neutral. Any help would be great.