Sharky6

Bit of a strange story on this car, so i’ll keep it as brief but explanatory as possible. Picked up the car a year ago with 120,000 miles. 2002 CLK430 cab. It was driving really nicely for a good while! I did some maintenance that was needed (valve cover gaskets, spark plugs, air filters, oil, etc.) and it was running really nice with the new stuff. Eventually, I got codes p0171 and p0174 and p0104. Lean on both banks and MAF circuit code. Tried replacing the MAF to no avail. It was a cheap one, so maybe I should try the repair again with a good quality one. Drove the car lean for a little while, and then the valve cover gaskets started leaking again- onto the exhaust manifolds and into the spark plug wells. Bad quality gaskets? Improper installation? Not sure. So, I took upon myself to do some more repairs. I also found a vacuum leak from Cylinder #4 injector, causing p0304(misfire.) I bought new plug wires, new VC gaskets, new injector seals, and since i wanted to remove and clean the intake manifold: new intake manifold gasket. Put it all back together- plugs, wires, valve covers, intake manifold, throttle body, injectors. Start it up and boom- the reason i’m making this thread. It starts, idles super low(~400), revs itself to 3000rpm, and then dies right after. If I give it some gas it can hesitatingly stay alive for a couple seconds longer but it eventually dies. I definitely installed SOMETHING wrong for this to be happening. Is this indicating something specific? Big vacuum leak? Electrical problem? Fuel thing? I’m not sure where to start. Any feedback is appreciated

LateLife Crisis

I'd be checking for vacuum leaks off the 4 breather hoses running off the top of the rocker covers. Check the actuation of the inlet manifold valves. Check spark plugs leads are running to correct spark plugs, they have letters cast into the rocker covers. Not sure what a vacuum leak off an injector is. A leaking injector normally involves fuel leaking at 40 plus psi due to a faulty O ring. Your basically looking for any leaks after the MAF which will cause the car to run lean.

andy_breuer

I’ve got a similar p0171 p0174 code issue now and am working all the steps. I’ll let you know how it goes. I’d double check that you got the spark plugs (all 16) re-attached in order and tight.