after a wile I pout a new motor into my e250 I remind you the other thread.. thing runs ok idles with a bit of a shake and the exhaust has a little lope to it.. CEL comes on gives the code P0340 and the one for the Bank 1 O2 sensor upstream... go buy both sensors and change them and the P0340 comes on again twice once its pending... being I changed the sensor where do I start trying to find out what is wrong with this hunk of crap now?