I usually get about 2-3 weeks without any issues on my 04, then something creeps up. Well, now it has developed a little hard starting, idle winds up, then comes back down to under 1k, then just drops and dies. Checked the codes and got a whole mess of them:

• P0414 - secondary air injection switching valve A
• P0445 - EVAP purge control valve
• P0448 - EVAP vent control
• P0102 - Mas air flow A circuit low
• P0340 - Cam position sensor A, bank 1

I assume most of these are related to maybe one or two issues, so I started researching the P0414 code. Watched a few videos from Atlantic British and noticed I don't have a secondary pump. Maybe that means I don't have a Bosch engine? The previous owner actually relocated the coil packs to mount in the same area as where the secondary pump would have been.

Given the codes listed, where should I start first? I'm a little lost on this one.

Thanks

 

Usually a bad MAF, start with that.

 

I've used MAF sensor cleaner on it previously, but that was months ago before these codes popped up. Would a bad MAF sensor cause other related issues and the other codes? As in, would a bad MAP sensor eventually cause the EVAP codes or the secondary air injector code, or would an issue with one of those drive the MAF sensor to go bad?

 

Sorry, looking at it now, the bad maf is responsible for the last two codes, the first three are not related to that and shorts to ground in your wiring harness. Download the rave and check the wiring diagrams - check the positive wire on each of those devices for short to ground.

 

Well, doing more research on the first two codes led me to realize my Disco had the SAI stuff removed at some point by a previous owner. Makes sense why I wasn't seeing a secondary air pump mounted on the passenger firewall area. Looks like two ports coming out of the head on the passenger side are capped off, a couple of hoses are capped at an EVAP/air controller thing on top of the driver valve cover, and the air check valve is removed from next to the passenger valve cover.

I'll go ahead an get another MAF sensor and check wiring diagrams for the EVAP/air controller thing...whatever it's called.

 

It might be just about as cheap for you to just switch to a non-SAI ECU at this point instead of trying to put everything back on it, assuming you do not live in Cali. You will need a matched ECU/BCU for it to run, and an IC or Nanocom if you don't want the mileage to flash at you.

 

I'm still struggling to figure out what is going on. Trying to test the MAF sensor operation and can identify two wires with power on, but not sure about the other three. One seems to be the ground, and the other two would be signal to and from sensor. The power wires were reading around 6 volts each...not 12. Once the engine is running, the in/out sensor wires are barely showing .08 to .10 volts and don't seems to fluctuate much when I slowly rev the engine. I thought a noticable voltage change should happen when engine revs.

Once the engine gets up to a higher temp, the idle will drop off and die. Until then, it idles rough. I took the intake off to check the MAF sensor wiring harness and I don't see any kinked or melted wires. I could have been checking the voltage incorrectly...at this point I'm not sure what to zero in on. Any suggestions?

 

Also for got to add...there is no difference in the engine if I have the MAF sensor plugged in or not. I also put in a different MAF sensor, and ran the engine with sensor plugged in and not plugged. No different. That's what was leading me to a possible issue with wiring, but didn't see anything.