why my 03 bmw 745i has i change all my coils and spark plugs cant find the awnser

Question

how can i solve it cant pinpoint the problem p0316 p1347 p1353 p1348 p1350 p1356 p1343 got new coils n spark plugs .i got p0492 p0491 could that be the problem?

Answer 1

P0316  Multiple misifre

P1347 Multiple misfire

P1353 Multiple misfire

P1348 Multiple misfire

What you hve is a multiple misfire that is catalsyt damaging.Is there any engine noise such as a rattling noise from the front.? How is the oil level. Overfilled oil level can cause a multiple misfire. As long as there is no front engine noise a plugged exhuast system can cause all the misfire event you have.

 The timing chain would be the last suspicious event that would cause the misfire. If there is a front engine noise, the timing chain gaurd may have slipped out, Here a 740i where the timing chain gaurd  broke internally, this cause the jump gaurd to break and damage the timing chain tensioner. If the misfire condition is  not resolved very quickly it can cause problem with the timing chain as well as damage the catalytic convertor.