3.4l

Getting codes for multiple misfires and lean banks. Car barely idles, goes from 250rpm to 800rmp, up and down until it dies. If I 2 foot brake and gas, it runs phenomenal. Fly down the road, but when I slow to turn or stop, wants to die. Coils? MAF Sensor? Has fresh gas, new heads and intake...

The 2005 Buick in question started with a rattling engine noise and loss of power; engine did not overheat and or leak any fluids. Rattle noise heard on higher RPM but not heard on idle. Previously, P0420 code for which nothing done due to running fine. any ideas to look for greatly...

Can I use fuel line hose to replace oil cooler hoses on 3.4L? i had to remove the oil cooler ( oil filter location in order to replace 2" kburst hose) I have 5/16" fuel line but I sure don't want to have to do this twice.