1/4 CEL AND NOW 5/8 CEL

I finally had a chance to work and drive my 348 this past weekend.

Jeff,
Per your suggestion, I unplugged the tempurature sensors to see if there was a short that was causing my radiator warning light to come on. The light still came so I guess there is a short somewhere. Where do I start?

Both CEL lights came on right away and the car took 3-4 tries before it started. I also had to "feather" the throttle to keep the car running. It stabilized in less than one minute. Prior to this in my original post, the 1/4 light was on. I swapped the o2 sensors and only got transient CEL's. Could unplugging the tempurature sensors cause them both to come on?

I pulled the codes for 1/4 and got the same one's, 4121, 1212, 1211. I couldn't pull codes for the 5/8 side but I will try again later. Should I just replace the o2 sensors and the crank sensors? o2 sensors are easy, but I don't know where the crank sensors are. I was not able to pull a plug to see if the plugs are running rich. Will do so soon.

You also asked about service history. The car got a full engine out service in October of 2008. This service included a new clutch.

Thanks for all your help (Jeff and all in the brotherhood).

 

I would try the 02's first, I believe those are the codes I pulled when mine when bad. Bosch Universals are great and priced right. The crank sensors are under the car near the alternator, easy to get to when the car is in the air. I highly recommend you get a gold connector kit too, a lot of the errors in these cars are caused by bad connections.

Here is my old thread from when I first purchased my 348: http://www.ferrarichat.com/forum/showthread.php?t=236347&highlight=4121


--Mike

 

I'd vote for cleaning & reseating the ECU contacts first.

 

Not sure how reliable those codes are. I remember having the "phase sensor" code along with some other ones that I'd have to look up.
I started replacing what the codes suggested.. kind of a waste of cash.
the only thing that I replaced that fixed anything was those expensive ecu things that monitor the exhaust....
phase sensor was a false positive ) so to speak.
most of what caused all the issues on my 348 were connector related, found the last one
by wiggling the connector on the MAF. after cleaning those guys and making sure the connectors were seated the ck eng stopped.
Until the fuel regulators went bad, but that's a different story.
I feel your pain.

 

I will go back and thoroughly clean all the relevant connectors before replacing anything. Though nothing so far looked at all dirty or corroded I will spray and brush with CRC and then apply Stabilant 22a.

Just received my laser thermometer and checked the cat temps. They were 430 f degrees.

Thanks for the help.

 

Don't forget to check that big honkin' screw connector that feeds the signals back to the
ECUs

 

by big honkin screw connector, do you mean the one near the driver side rear shock tower?
I cleaned it but will go back and clean again and apply Stabilant 22a.

Thanks

 

Yeah, that's the one. I had trouble with my 348 tracking those codes down, because I'd get different values at times. I confused me.
I also used that sabilient22 stuff but doubt if it made a difference, may be it keep things right after cleaning everything.
the other thing someone mentioned was the ecu connectors (inside the car).
those guys have to be disconnected when removing the engine for service.
Were all your codes relate to exhaust errors?

 

Yes, I got 4121, 1212, and 1211. Reading the many threads they are all related. I will unplug the ecu's and clean them in addition to all the other connections and post the results.
Thanks

 

And how was this problem solved? cleaning connectors?

 

Apologies for the delay in response to all that are trying to help. Bosch 13120 O2 sensors just (finally) arrived and installed last night. Will set the MAF's tonight and let you know the results. Keeping my fingers crossed.

Thanks

 

Make sure you set the MAF's to 384 ohms each and then do a relearn with the new 02's before doing the more intensive 02 tuning of the MAF's. You will be also sure that you have the codes all taken care of too.

--Mike

 

This pretty much sounds like my life with my 348 prior to installing Dave's connector kit, even including hard starts and variable idle (having to feather the throttle so it wouldn't die).

I used Stabilant 22a and although it initially offered some slight improvement, it builds up a varnish-like layer on the connectors and makes things worse over time, in my experience. Like you, my connectors weren't dirty or corroded - I am of the belief that the primary cause of the problems is that the clamping pressure of the connectors goes out of spec, and it continues to get worse the more you disconnect and reconnect the sensors.

Dave's kit solves the problems once and for all - or you can do like I did and chase ghost issues around for years, replacing sensors, cleaning connectors, resetting ECUs and pulling your hair out until you are ready to push your car off a cliff. If you really want to replace your crank sensors, at least try the Kia ones first (link in my sig) before you spend a bunch of bucks on something that may not really need replacing.

 

+348

 

In hindsight, Dave's kit should be installed first - most (if not all) of the issues go away, and any remaining ones are real and not a product of faulty signals to the ECUs. Then, and only then, can benefits be realized by dialing in MAFs, etc. when the ECUs are recieving correct info. Good luck to the OP, been there and done that, I know exactly how frustrating it can be!

 

Well I put in the new Bosch O2 sensors, cleaned all the contacts, and set the MAF's to 383 and guess what? It started instantly, no faltering, and no feathering of the pedal needed; just a nice smooth idle. Then a 30 minute drive and still NO CEL'S. Plus I cleaned the two tempurature sensor contacts under the plenum now NO MORE RADIATOR WARNING LIGHT!

Thanks to Jeff, Mike, Dave, Eric, Clyde, tamf328, Jasperd and all the Brotherhood for your help! You guys are the best!

 

Very good too hear. As stated above a few times, the next step is to get a gold connector kit. Your old connectors will continue to degrade in both hold and connectivity and problems will creep up again.

--Mike