My brother needs help. CTSV spitting/sputtering

**Lunatikgixxer** · 09-15-2011, 06:48 PM

He has a 2004 CTSV with the ls6 and a vortech supercharger. His car has ran great since he bought it 3-4 years ago and as far as i can recall this is the first major problem hes had. He said its running like shit and its spitting and sputtering and dumping a lot of fuel into the cylinders. He also says its throwing a code P0300 and hes changed the Plugs/Wires. Checked the injectors and cleaned up the MAF and it still is running bad. Any ideas?

**pajeff02** · 09-16-2011, 03:37 AM

Vacuum leak? O2 on its way out? Fuel pressure issue? How did he diagnose the overfueling?

**Lunatikgixxer** · 09-16-2011, 05:42 AM

he has an A/F gauge and maybe he was reading rich off that. Ill find out more today

**ls1camino** · 09-16-2011, 07:02 AM

What do the plugs look like?

**Lunatikgixxer** · 09-16-2011, 08:31 AM

Like i thought, he said he was reading his A/F ratio gauge and its pegged in blue, running rich. He said you can also smell it and see smoke coming from the tail pipes. He said if he unplugs an injector (any injector) the car will start to run better and the A/F guage balances out but it misses because of the missing cylinder. Sound like a fuel problem to me. He also said he found out on his car the ECU is up in the front bumper, his car is a DD and its been raining A LOT the past 2-3 months and he said he might of screwed that up driving through some flooded roads? who knows.
Camino he said they were black and burnt looking.

**cammed goat** · 09-16-2011, 09:10 AM

Mileage?

**cammed goat** · 09-16-2011, 09:25 AM

I am inclined to believe it is a pre-cat O2 as if it were ECU-related, and it, indeed, got wet, the car wouldn't fire at all. Was the MAF checked? What tune is running in it? Normal? Speed-Density?

**Lunatikgixxer** · 09-16-2011, 10:23 AM

He actually replaced the MAF with a new one and it did not fix the problem. He hasnt done the O2s yet but thats next on his list. Jeremy formato dyno tuned it about 2 years ago i cannot tell you what kind of tune it is.

Mileage is somewhere around 40-50k

**cammed goat** · 09-16-2011, 01:11 PM

If the MAF is remanufactured/aftermarket, that could be the issue. I had an 08 Isuzu Rodeo come into my last job for a frame inspection. It also had a CEL. I hooked up the Tech2 and found the MAF was causing an issue. Upon looking at the MAF, which looked clean, I noticed a bar code with "REMFG" or something like that staring me in the face. Upon notifying the advisor, I was told to back it out as the owner of the vehicle was throwing parts at it, not actually fixing the problem. Keep us posted.

**Cutlass** · 09-16-2011, 05:55 PM

if your concerned about the PCM, pull the connectors off and check for corrosion. I've ran into that twice on a couple Cadillacs. Its rare but can happen. Otherwise, those PCMs are pretty well sealed and can hold out the water well.
Does it run crappy cold, or only when its warmed up?
Try to get the thing to run in open loop by disconnecting the O2 sensors. If it runs better in open loop then suspect the O2s as a problem. If it still runs crappy, suspect other things like high fuel pressure, leaky injectors, bad coolant temp sensor, bad MAP sensor, etc.

**Lunatikgixxer** · 09-16-2011, 09:46 PM

Originally Posted by cammed goat

If the MAF is remanufactured/aftermarket, that could be the issue. I had an 08 Isuzu Rodeo come into my last job for a frame inspection. It also had a CEL. I hooked up the Tech2 and found the MAF was causing an issue. Upon looking at the MAF, which looked clean, I noticed a bar code with "REMFG" or something like that staring me in the face. Upon notifying the advisor, I was told to back it out as the owner of the vehicle was throwing parts at it, not actually fixing the problem. Keep us posted.

No, he had his stock MAF on when the problem started, Then he replaced it with a new MAF and it didnt change anything...

Originally Posted by Cutlass

if your concerned about the PCM, pull the connectors off and check for corrosion. I've ran into that twice on a couple Cadillacs. Its rare but can happen. Otherwise, those PCMs are pretty well sealed and can hold out the water well.
Does it run crappy cold, or only when its warmed up?
Try to get the thing to run in open loop by disconnecting the O2 sensors. If it runs better in open loop then suspect the O2s as a problem. If it still runs crappy, suspect other things like high fuel pressure, leaky injectors, bad coolant temp sensor, bad MAP sensor, etc.

Last time i talked to him he said he was replacing the O2s, i havent talked to him since. I will talk to him tomorrow and see what he says. If its not the O2s i will let you guys knows. Its kinda weird IMO. When i had my O2s disconnected my car never smoked or dumped massive fuel into the car..