Having some wierd stuff going on, need direction.
I am having trouble with sputtering under load, a scan in hp tuners shows bank one ltft adding like +25 and ltft bank 2 going negative like -12

I checked the usual stuff like vac leaks header gaskets and such but wtf?

Car is basically undriveable it idles fine but once underway it putters if you apply any kind of throttle.

any idears where to look? i recently disconnected pcv and added more crankcase breathing due to blowby. It s a speed density tune with twin turbos

 

A huge split in LTFT's between left and right can only be a few things
Either a major exhaust leak
or most often a failing 02 sensor-----
I would check your front 02's to see if both are working correctly
Try to use a scanner that reads real time data---Your 02 voltages should rapidly change between .100 to .950 millivolts and have an average voltage of about .450 to .500 millivolts A bad 02 will FLATLINE on .450 millivolts and NOT oscillate between .100 and .950

Finally A clogged or BAD cat converter will cause the same symptoms-----
You can take your car to a muffler shop and they have a tester that will show if you have a clogged cat side to side----( a good cat will have less than 1 PSI backpressure at 2500 RPM's But a bad cat will have a much larger PSI back pressure---)

 

thanks for that reply. I was onto this idea so i removed the mid pipe and looked at the cats no blockage visible then i installed a flashlight from the back and looked in and saw a very faint spot of light so it appear cats ok but i am going to call around and see if i can fond a shop that does this test i was unawares there was such a test thanks.

As for the 02 sensors i replaced them a couple month back they are ngk and i was sceptical as i usually demand bosch. I think maybe your right about these as when i am scanning the trims go dead for over a minute and when they are trimming the voltage doesnt swing more than 200mv and stays on the rich side like 700-875 mv when they do swing.
I have no ex leaks anywhere.Also no turbo ducting leaks wondering if intake can blow out seals side to side?












I would check your front 02's to see if both are working correctly
Try to use a scanner that reads real time data---Your 02 voltages should rapidly change between .100 to .950 millivolts and have an average voltage of about .450 to .500 millivolts A bad 02 will FLATLINE on .450 millivolts and NOT oscillate between .100 and .950

Finally A clogged or BAD cat converter will cause the same symptoms-----
You can take your car to a muffler shop and they have a tester that will show if you have a clogged cat side to side----( a good cat will have less than 1 PSI backpressure at 2500 RPM's But a bad cat will have a much larger PSI back pressure---)[/QUOTE]

 

Each bank has a fuse to supply the coils with power. Make absolutely sure that you have full battery power on those fuses. Measure each test point on top of the fuse to chassis ground.

There is a GROUND on the back of the drivers side head for the coils. MAKE SURE that ground is not loose or damaged!

What do the volt meters in the car register when this issue happens? Do you have any LOW VOLTAGE DTCs on any other module???

Your O2 sensors have heaters. The OXYSEN fuse supplies 12 VDC to those heater circuits. Measure the voltage at that fuse to ground. I also recommend checking the ground for that heater circuit to insure that it has proper continuity.

If the heaters don't work, the sensors will be inefficient and or fail early!.

BC

 

this may help got a cel last night dtc says p0200 or injector curcuit fault. where do i start looking? thanks guys edit again i went and checked bat voltage and its 11.5 sitting in the car with koeo. I am going to take it back for repalce and report here again i know that anything less than a full voltage will cause all kinds of wierd chit to anything electrical on these cars had this problem before back in september.

 

Damn Im good!!!!

Here is the schematics for the coil circuits. The Hot at ALL Times feed comes from the IGNITION SWITCH. If that feed fails, the
coils will shut down.

If the fuse 16 or 22 fails, it will trip the P0200 DTC. Been there done that. SO,,,, Something is causing current/voltage to quit at fuse 16 or 22. Pull the fuse and see if that code pops up. I drve my car 10-12 miles on ONE BANK. Now I know what it like to drive a 4 cyl C5.

Make sure that the fuse is TIGHT in the fuse holder.. If its loose, it will fail. Bust a fuse in half and insert that blade into the fuse holder slots. The blade should have good resistance to insertion and extraction.

I PINCHED THE PINK FEED WIRE after the fuse and when I had heavy acceleration, the wire would short out, blow the fuse and I got the P-0200 and one bank failure.

 

thanks Bill. battery removed and taken to shop for testing came back ok will try your step by step below tmrw after work

 

for future review. I found a broken pink wire to number 1 injector. fixed it. then car then threw code 01300 bad 02 sensor heater. removed sensors one was not colored right replaced with 2 new bosch sensors $38 ea runs good again. fwiw the sensors that failed were ngk 2 months old less than 5 tanks of gas run on them they are junk stay away.

 

new cel to this saga

i am getting codes 0141 0161 02 senor heater curcuit malfunctions.

Where to look

 

YEP, Discussed the heater circuit issues back in reply four.

Here is the schematic that you will need. ITS CRITICAL that you measure the SUPPLY VOLTAGE that comes from the ignition switch.

Then you have to make SURE that you have a good ground path for the voltage and current to escape. BOTH can cause heater circuit failure.

The POWER comes from the HOT in ON circuit (The IGNITION SWITCH) and that is a point of FAILURE. You MUST have full battery voltage at that fuse or the switch is FUBAR

The ground need to have full continuity to chassis ground.



Bill

 

Splice pack SP-122 has been a source of failure on some cars. Its very close to the acid path of a bad battery and has been known to corrode over due to acid / acid gas exposure. Pop the top off the SP that's behind the battery and taped to the main harness:

AS FOUND CORRODED:




AFTER CLEANING:

 

ok i put 2 new bosch sensors into banks 1 car runs now but i am getting slight misfires everywhere no codes. the header pipes all get warm the same . the plugs look good. the wires are fine. i pulled wires individual and all resulted in same symptoms, more misfire, also did same with injectors and engine got rougher as i disabled each so i know every cylinger is firing.. fuel pressure good.you feel it slightly at idle but is real bad when you drive in a higher gear like say 40mph and lug it in 6th, the car shakes as does the shifter real bad.Bill it seems when a load is put on it gets worse like weak maybe it is a current thing either to coils or injectors, does this all run up from the wire on the starter solenoid? cause i get a slight skip when i turn the key to start the car and think maybe its a lose wire down there i had this problem once before 2 yrs back

 

LOL!! I know EXACTLY how you feel//// I installed a new SPEC Twin clutch. Lower inertia smaller diameter. That resulted in NUMEROUS misfire reports. I had my tuner desensitize the knock sensor reporting and problem solved. Don't eliminate it,, just desensitize the reporting threshold.

A BIG cam can do the same thing as well as a CAM gear drive system.

Thoughts??

Bill

 

the clutch does rattle some but i have my knock gains lowered and there is no retard on my scans. I can try this and see what happens clutch is actually statitng to slip its getting old and so am I