Throwing 4 codes at once any advice?

[jtappan]

Hey first I apoligize for making this my intro post. I did some searching first but before I go throwing alot of money into the wrong parts maybe this combination of codes will help narrow my problem down. I just got all 4 of these codes at once. Any ideas or suggestions are greatly appreciated.

That said glad to see all of the writeups on the site very helpful. Thanks!

P0401
C2900
B1805
U1262

 

[jjcool00]

Could you provide more info, year, model, engine size, is it running rough, driving fine, symptoms. At first glance seems like you are having an air flow issue. Do you have an aftermarket intake in? Maybe it's not sealed, does the car drive differently in the rain? I would start with the Intake then the MAF and EGR.

 

[jtappan]

My apologies. I was posting quick at work. It's a 2004 Lincoln LS V6 all stock

 

[02LincLS]

Seemingly unrelated codes. Not much info to go on but either the computer is on the way out, or you have misfiring COP's causing electrical interference on the computer. I think this is why JJcool asked if it was running rough.

 

[jtappan]

supposedly the shop said the exhaust is just clogged

 

[jjcool00]

When I bought my car it had some garbage Spectre intake on it and it caused a couple of those codes. Makes sense that it's the exhaust since it is air flow related. Once I got rid of the Spectre and put the K&N intake on it I had no codes, no issues.

 

[Telco]

P0401- Insufficient EGR flow, most likely a dirty EGR valve. You can try cleaning the one you have. If you get a new one get a Lincoln one, not a universal from the parts store as they tend to not work correctly. You may also have some buildup inside the intake where the EGR connects. That stuff can be pretty hard too, so when you clean it out make sure to use a vacuum to clean out the bits.

C2900 - Not finding anything on it. May have to check a factory LS manual for your year to see what it is.

B1805 - Lamp Turn Signal Rear Output Circuit Short To Ground, check your rear lights. You may have a defective bulb, or the socket may be defective. Worst case scenario - a wire has rubbed the insulation off somewhere which is a major pain to find.

U1262 - SCP (J1850) Communication Bus Fault - May not be a real code. A lot of the network codes can be set for whatever reason but actually won't affect anything. Someone with a factory LS manual for your year will need to check and see if this is a real code.