Weird Codes P0108 & P0406

[HANN4S]

I have a 2003 Lincoln LS V8 with 80k. It has been very faithful. No major problems in the last year. But lately, the engine light came on and decided to stick around for the fun rides. The car is running well. It's not acting up or being weird in any way except for the engine light smiling at me and keeping company. I took it to Autozone to have it read and two codes came up. The codes definitions are listed below. I suspect that the problems are related but i cannot be sure. I just don't expect two different things to be wrong with the car at the same time. One must be causing the other or something. I also confess that i haven't changed the air filter and cabin filter for ages. Every time i take the car in for an oil change, i'm told that they are fine. Lately when the heat is on, cold air blows on the passenger side but when it does get warm after a long drive, it doesn't blow as hard as it does on the driver side. I suspect the heater core or DCCV. Are these all related? Has anyone encountered these codes before? What should i do? Thanks

P0108

MAP (Man. Absolute Pressure) BARO or MAF (Mass Air Flow) /VAF (Vane Air Flow) sensor condition.
Probable Causes:
1. Vacuum hose off, cracked or passage blocked-Engine mechanical timing condition.
2. Throttle body intake tube loose, off, or cracked
3. Barometer/MAP (Man. Absolute Pressure) defective
4. MAF (Mass Air Flow) /VAF (Vane Air Flow) sensor dirty or defective

P0406

EGR system fault (Exhaust Gas recirculation)

Probable Causes:
1. Failed EGR position sensor
2. Open or short circuit condition
3. Failed EGR valve
4. Failed EGR pressure sensor where applicable
5. Failed EGR position sensor where applicable

[shorod]

I too suspect the codes are related, but completely separate of the heater issues and DCCV.

I'd start by looking closely at the few vacuum lines under the hood as well as the throttle intake air tubing. Make sure it's properly connected and securely attached.

If all of that checks out, check the battery in the spare tire well. These cars have a very sensitive electrical system and with your car being a 2003, if the battery is still original, it's on its last legs. Before spending a lot of time on the codes or the HVAC system, you might consider investing in a new battery as you'll soon need it anyway.

-Rod

[HANN4S]

Thanks for the reply Rod. I replaced the battery around this time last year with about 65,000 miles on the car. I'll take it to the shop and have them check the vacuum lines and the throttle intake air tubing. Hope to find a solution soon.

Thanks

[Txman437]

The codes are for the electronic EGR valve and connector being faulty. It has to do with the exhaust gases that are put back through the manifold. Both parts need to be replaced. I just spent $95 at the dealership to tell me what was wrong. I'm not certain it's a do-it-yourself job yet. I'll do some more research and find out.

That's pretty much what was posted up top. I was hoping to see if anyone found this to be the case. I was told replacing the valve/connector would fix the problem.

[HANN4S]

I replaced the DCCV and i'm finally getting heat on the passenger side. It was clogged.

[shorod]

Originally Posted by HANN4S

I replaced the DCCV and i'm finally getting heat on the passenger side. It was clogged.

Can you tell what it is clogged with? That doesn't look like something normally found in the cooling system. I hope you flushed the cooling system after putting everything back together!

-Rod

[HANN4S]

It was a gooey stuff sort of like petroleum jelly. Yes the system was flushed afterward. Thanks