Hey guys, sorry ive been MIA lately... its been a very busy summer! So, my CEL came on the other day, and today i'm dealing with it. Codes 4121 & 1112 Altho I dont understand the 4121 because my CAT ECU's are disconnected, and have been for years! So, i'm cleaning the MAF's and I figured it was time for a new set of plugs too... I feel like a tard because I cant get a socket on the damn plugs!! Every thing from 5/8" and up just spins! Whats the joke here?? I can't see down the holes to the hex... help??
You need an 18mm deep socket to get the plugs out. One comes in the factory supplied tool kit, it fits any conventional 3/8" drive ratchet or extension.
Hey Steve, don't forget to clean both ECU contacts as well as all engine sensors .... Hope this is nothing !
That's the reason for the code. The Motronic doesn't "see" the signal coming from the cat ecu's so it thinks they are broken. I always get that code because like you I don't have the stupid things in my car at all. The good thing with our cars is that it is a silent code, meaning the Motronic only stores the code but doesn't trigger the CEL light.
Make sure you tip the end with spark plug rubber or good luck getting them out, or worse back in again lol
your ECU you keep disconnected? assuming bc cars been garaged? you cannot start the car with out having it connected correct? How come you leave it disconnected?
Steve and Ernie are talking about the ECUs for the catalytic convertors being disconnected, not the main ECUs which run each bank of cylinders. Steve, although the stock plugs need an 18mm socket, if your car has been upgraded to the NGK plugs they are a 19mm socket.
Hey guys, thanks for all the tips and input! Yea Ernie, thank god the 4121 code doesn't trigger the CEL! Anyway, I cleaned up my MAF's really good, and reset everything, so far its running smooth and normal again. As far as the plugs, I havn't replaced them since I bought the car, so I figured it was time. I cant find the NGK-DR8EIX Iridium plugs ANYWHERE locally, so I ordered them through the NAPA store down the street, i'll have them monday. The plus in there are the chitty OEM recommended Champion plugs, and they are in fact 18mm. I did try to take the #1 plug out to take a look... couldn't break it loose with my simple hand tools, so this is gonna be fun!
Time to get out your breaker bar and BFH!!! When you put the new plugs in run a coating of copper anti-seize lubricant over the threads so you don't have to deal with that crap again.
Steve...If you don't mind me asking...how much from NAPA? I found mine at sparkplugs.com and was delighted with the price but that was 3 years ago.
$9.99 each, and they made me buy a full box of ten. So, 15-16 years and 4 tuneups from now, I will have acquired a complete set for my 5th tuneup sometime around 2031! The cool thing about that is, the car will be 40 years old and an antique! Maybe by then it'll be worth what I paid for it in 2007 again! lol Then again, it'll have roughly 150K miles on it by then, so it'll probably be worthless....
When looking for these plugs, you might also try local motorcycle shops. The NGK DR8 spark plug is a very common motorcycle spark plug. The EIX is just the iridium version (which is, of course, less common).
The prices, above are really good. I don't sell the EIX version in my motorcycle shop, but I looked up what my shop would pay (wholesale) to buy them and they're $6.19 Suggested retail is $10.50 each.
