P1133 on 97 Chevy van 5.7L
I tuned up this van last May with 100k + miles. Big improvement but still got P1133. Replaced bank 1 sensor 1 and all was well until last month. Started spitting and coughing when cold. Got multiple codes incl backfires and P1133 again. Called bosch and they said sensors don't fail (HA!) and that it could be Bank2 Sensor 1 since they are tied together. So I replaced that one as well. Still getting performance problems for 1st miles or so and got light on again today with P1133 twice. Is it the first sensor failed again or something else???
I'd replace the B1S1 O2 with one from the dealer. Alot of people here have had problems with Bosch (and some haven't). Good luck and keep us posted.