My 2003 Disco CEL came on with:
P1412 (Secondary Air Injection System – Malfunction Bank 1 LH (Insufficient SAI flow during passive test)).

While I was trying to figure out what it really meant and what was the fix for it, the CEL then started blinking while driving on the freeway and the Disco really started running rough, jerky, and lower power. Low RPMS was especially jerky. The CEL is on when the vehicle is sitting but only blinks when driving. I now get:

P1300 (Random/multiple cylinder misfire detected / Catalyst damaging level of misfire on more than one cylinder)
P0301 (Cylinder 1 misfire detected / Excess emissions level of misfire detected on cylinder No.1)
P0306 (Cylinder 6 misfire detected / Excess emissions level of misfire detected on cylinder No.6)

The original P1412 codes are not showing up. The P0301 and P0306 DTCs get listed twice. I am using the Innova 3130 to get the codes.

I have replaced the spark plugs (the dealer had put some Champions in) with the Platinum Doubles. Didn’t really affect anything.

Cleaned the MAF with no appreciable change. Have not tried running with the MAF disconnected for a short period to isolate and see if that was causing a problem.

I am leaning towards having the ignition wires replaced. Also, feel that the ignition coils should be replaced as long as the plenum is off.

I am wondering if all this is the result of an O2 sensor (have all the live data from the 3130 but it appears in normal range) or MAF.

Really confused with the overload of information others are giving me. Based on all I have been told, I should replace the ignition wires, ignition coils, MAF and all 45 O2 Sensors. Seems like over kill on a Disco with 85,000 miles.

Please help????

Thanks - Kurt

P.S. The only LR dealer within 300 miles is an abolute nightmare to the point that local repair shops don't fix LRs as they don't want to get parts from that dealer. I realize that I would have to go to the dealer for the ignition wires and coils. But if I know what is the problem, then they won't continue BSing me.

 

ok...where to begin.

For future reference, a flashing cel means raw fuel is getting to the cats and destroying them. You cats (not the furry ones) can take an ocassional sip of fuel, but not everything 2 cylinders have at any moment. I would stop driving the vehicle for now. or at least you get it running to the point where the cel isnt flashing.

you have two misfires. cylinder 1 and 6. swap the wires for 1 and 6 with 2 and 5. Run the vehicle again. check the codes. if the codes move to cylinders 2 and 5. Its the wires.
If they dont, its the coil or the ecu. Smart money would say replace the coil before you replace the ecu.
Diagnostics made easy. let us know how that works out for you.

 

as far as the SAI codes, this is direct from rave.

Flow Fault Finding chart

1

2

3

4

5

6

7

8

9

10 Delivery Hoses – Check for: Blocked/leaking hoses

 

Very interesting. I though that the firing order, etc was very specific and that any change and the engine just wouldn't run. I will try the swap tomorrow. Extremely ingenious!!

Regarding the troubleshooting of SAI, the indication seems to be it is affecting the left side. In relieving any potential blockages, I assume it would be a buildup of carbon. Would pulling the connectors and shooting some Gumout or some other cleaner be of any help? The worry would be in creating further problems.

 

is the coil a balested or nonbalested coil? I boiled 2 balested coil when i should of been using a nonbalested coil

 

First leave the coil alone, install a new set of 8 mm wires, clear the codes then deal with the SAI codes.
By the way, how many miles on the engine and what octane gas are you using?
As for cleaning the MAF, first of all you had no codes indicating a MAF failure and cleaning our MAF's, especially when not indicated can kill them.
In the future, ask your questions first, get feed back then act, you may save some money.

 

He wasn't talking about changing the firing order. He was saying to completely change the wires for those two cylinders. Unplug the wire at the spark plug and the coil, and replace it with a wire from a cylinder that is not misfiring, then put the wire from the original misfiring cylinder onto a cylinder that did not have a misfire. The wire routing will not be changed, so the firing order will remain the same.

Or, just replace the spark plug wires if they are original, like Mike is suggesting.

 

You never, especially on a SAI engine, replace only a couple of wires, you replace them all. Why go thru all that hassle when his factory grey wires are long since shot also?

 

Mike, thank you for your response. At this point I assume that the P1300, P0301, and P0306 should be rectified with new wires. Considering all the work that goes in to accessing them (removal of plenum) I thought I might as well replace the coils as well.

My 2003 Disco has 86,000 miles and ALWAYS Premium fuel (around here that is 91 or better). I was advised to use Seafoam every 2500 miles also.

I am beginning to see that the P1412 code will be a challenge as it seems to be connected to a lot of items that can trigger the DTC.

I love this car and don't want the Dealer to screw it up any more! I anticipate I will buy the ignition parts and find a local mechanic that works on LR to install them as removing the plenum seems a daunting task from looking at it. I do I have the RAVE manual and am slowly getting used to navigating it.

Thank you for your guidance!
Kurt

 

Why pay to have someone else do the work, save a bundle and let us walk you thru install the wires?