Hello, I am working on a 94 348 spider. Recently installed test pipes with stainless exhaust. 1-4 CEL illuminates 5 min after startup and records 1211 code. Swapped left to right: MAF O2 sensors (with additional grounds) ECUs New coolant temp sensors Have not been able to get problem to follow to 5-8 Visually inspected wiring to all of the above with no obvious flaws. Have not checked continuity. Cleaned all connections with electronic cleaner. No dielectric grease used. Have reinitialized ECUs several times. Checked intake for air leaks, none found. Car seems to run perfectly otherwise. Any ideas?
Time for new O2's.... Get Bosch universals. 1211 is a Lambda code. Test it by pulling your O2's at the wire plug and run the car after clearing the codes. --Mike
cut and pasted from my348 dot com Lambda regulation Additive value for self adaptation (O2 sensor or coolant temperature sensor or MAF) 1211 Lambda regulation multiplicative value for self adaptation 1212 Lambda regulation intake manifold compensation (MAF or O2?) 1212 (1213?) *Lambda codes 1211 and 1212 refer to the fact that the emissions O2 sensors are going full tilt to regulate fuel mixture and it's still not enough. I would unplug them and run the car to add to the data base. If the car then runs normally then something in the O2 system needs to be considered. If on the other hand if it persists we can consider the code a sympathetic action. It could also be a problem with the coolant temp sensors. Way too many times I have seen a broken wire at that connector cause similar symptoms and it would also cause a Lambda regulation code. An open connection or high resistance at the coolant temp sensor will make the A/F mixture very rich. Something it can tolerate when cold but less so when you get some temperature in the motor. *thanks, rifledriver If the 1211 code appears on one side of your engine only, then you'll want to swap MAF's from your left engine side to your right engine side (this is also a good time to clean your MAFs by spraying starter fluid into each end of each MAF) and vice-versa. When you next drive your 348, notice if your 1211 code either returns on the same side of your engine (if so, then your problem is not MAF related) or if it switches sides to follow where you moved your MAF in the above side-to-side swap (which may very well hint that the MAF itself is the problem). If the1211 problem isn't MAF related per the above test, then swap O2 sensors from side to side when/if your code returns to see if the issue is related to a failing O2 sensor. See also: O2 If your 1211 problem isn't MAF sensor or O2 sensor related, then replace your coolant temp sensors. If this doesn't solve your 1211 issue, then you probably have a fundamental fuel mixture problem caused by any number of things such as a failing spark plug, bad spark plug wire, bad coil, failing alternator, failing fuel pressure regulator, failing fuel pump or bad fuel pump relay, cams mis-timed, etc.
Tested fuel pressure to 1-4 bank. Shows 40 psi at idle, and falls to 36-38 with regulator vacuum line disconnected. Repeated test for 5-8. Shows 50 psi, and increases to 55 psi with regulator vacuum disconnected. I think I need a new regulator and or pump for the 1-4 bank. My manual calls for 53 +/-3psi at idle. My experience with other makes with similar components tells me these pressure readings are a problem. Am I missing something? Thanks
Replaced 1-4 fuel pump and filter. Now have 53 psi fuel pressure. No check engine light, car runs fantastic. 1211 code fixed!
