I have a 4 bank SCT chip with all 4 banks being the exact same program. On 0, 1 and 2 positions, I get a re-occuring po174 lean bank 1 code. On 3 position , everything is fine, no codes whatsoever. Could this be a bad chip? Looked for any vacume leaks with a propane tank and all is fine, also checked the chip-cable and switch which also work fine.