So i recently did a single conversion on my 1jz and now it runs like ***** until it gets to operating temperature. My wideband shows it running at like 20 afr for probably the first 2-3 minutes of driving. Its almost like the ecu has to reprogram the tps every time i first start driving. It bogs and sputters up to about 50% throttle and after i get past 50% it runs like a champ and no problems till the next time i shut it off. Do you need a different map sensor that reads lower vaccum and higher boost after a single conversion? Is this dangerous for the engine running that lean at low rpm (no more than 2500-3000) for a minute or two, i make sure to not run higher until it resolves? thanks in advance.

 

Well running that lean can mess up your internals and cats if you have any. Have you gotten your car tuned sence you change to a single turbo?