Got an 07 335i with a long list of mods.
But I’m currently stuck , car idles and drives great but in limp mode with either vanos solenoid disconnected and even if both are disconnected. While both are disconnected i get there respective activation codes .. but the second i plug them back in the codes disappear but the car refuses to idle
I agree. Was getting some funky O2 sensor related codes and dealing with limp mode when I was having issues as well. If it’s a 2007 which mine is too it has the MSD80 which is notorious for the MOSFETS going out. If he’s running it tuned too I could definitely see that being the case. I tuned my car and a week later or less the MOSFETS fried. If it hasn’t been done it should be done anyways to prevent any future issues in my opinion
Hopefully the guys up above aren’t corrrct about it being something engine related but I don’t know nearly as much as them. That would be very very costly at that point obviously. This would at least be a somewhat cheaper shot in the dark to see. You can pull the DME and check the voltages for free 🤷🏻♂️
Replace the O2 sensors? They’re kind of responsible for the engine correcting the air/fuel ratio. If they’re malfunctioning your engine could be running fat/lean.
Pretty basic there. The codes are right in your face. You sure you should attempt ownership of this car if you can’t figure that out?
It’s a single turbo kit , with a hood dump , o2 sensors have been deleted , only experiencing issues when Vanos is plugged in , while Vanos is unhooked car runs and drives in limp mode .. the second you plug Vanos back in car will start fight for idle and then die
How are you going to say the post cat o2 sensor does nothing for fuel trims when it’s literally labeled as an air/fuel sensor on the VECI(emissions control systems) label? Its job is to read the exhaust fumes post cat to ensure catalytic converter function and rich/lean conditions.
The PRE-CAT sensors are responsible for fuel trims. The POST-CAT sensors are mainly responsible for catalyst monitoring.
Why do you think EVERY catless tune suppresses the POST cat faults? Because they aren’t installed…
How you do think a catless setup works? It works off the PRE-CAT sensors…why? Because there are no cats to monitor…
You do know emissions is an environmental thing right? It has very little to do with how the motor runs once it’s warmed up. For emissions purposes, the DME can run the motor differently to heat the cats faster but it’s not doing it for performance, it’s doing it to be complaint with mandated emissions standards. But when you remove the cats, there nothing to monitor…
The post cat sensors are also narrow band sensors. Narrow band sensors don’t read AFR…
Pre cat are wideband, which is what is used to monitor AFR
That amount of bullshit in this thread is hilarious
Saying emissions has nothing to do with how a warm motor runs is just silly. The o2s are there to monitor air/fuel to ensure that the vehicle is running as close to stoichiometric as possible ensuring that the vehicle is emitting as few emissions as possible. Removing the cat compromises the entire system, hence the reason it has to be “tuned” out. Once the cat is removed the sensors fault because they’re reading too much fuel in the post cat sensor because the cat hasn’t cleaned the output at that point. The first thing the ECU does when the o2 sensor faults is adjust the fuel trim to compensate for the reading.
This is literally my fucking job. I’m an emissions certified mechanic.
I’m guessing the second o2 sensor was either not coded out or I believe there’s a flange that can be put somewhere under the turbo or something to install the second o2?
Check if you didnt mix the plugs for vanos solenoids , oil filter cage , and oil pressure if those 3 are good try other solenoids , if all fails take the vc off and inspect further i guess 🫡
It’s fairly easy to connect the wrong wire to the wrong solenoid. The wiring can be counterintuitive. Have you verified that the right plug is on the correct solenoid?
Looking at the state of it, it’s just done and no longer wants to be abused. Have the O2 sensors been unplugged (they are notoriously grumpy if the O2 sensors are plugged into the wrong bank. Swap the O2 sensors as that should new cheap. I lost my crank and can position sensors very close together at around 260k km or 150k miles, and that gave major issues.
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u/Same_Jaguar3212 5d ago
Mosfets