codes... any ideas?

98GTBlk

New Member
Aug 31, 2003
59
0
0
Connecticut
hey guys. Last week i was out driving around and my car just started dying. While accelerating i noticed weird sudden drop offs in power and then when i put it in neutral the RPMs dived. When coming to a stop the car started idling really rough and began stalling out. Every time i would give it gas my rpms would DROP. so after having the car towed the following morning it started fine. the codes were gone because i reset it in the process of screwing with it. But today i got the codes to come back p0136 and p0156. I know that these are 02 sensor problems. I have a bassani modular off road pipe with MILs. The car has had an offroad pipe for a while and no CEL. so i put the cats back on for emissions (modular x pipe) and then took them back off again like 2 weeks ago and started getting CEL. I just dont understand how i could have both codes. Is my stalling problem independent of these codes? Any help would be appreciated. I searched and found possible fixes being exhaust leak, and bad MILs. Im pretty sure i dont have leak. Just to be sure... these codes arent normal just indicating no cats right?
-matt