P0174 Intermittent
Thread Starter
Member
Joined: Jul 2018
Posts: 171
Likes: 34
From: USA Tennessee
2008 SL550 R230, 2004 E320 W211
P0174 Intermittent
I am getting CEL and a stored P0174 (System Too Lean Bank 2), 2004 E320 with 170K miles. Spark plugs and wires are fresh.
Originally, I had no codes, but the throttle response was delayed. I cleaned the MAF and this improved slightly. I replaced the MAF (Bosch 0280217810 from Amazon) and throttle response was great, and I thought the problem was solved. However, about a week later, I got the stored P0174 code. I couldn't find any loose vacuum hoses, and checked that MAF was properly seated. I cleared the code and everything was fine, but P0174 came back after about a week. Everything is running fine with no other symptoms other than the CEL.
I have SDS, and I could test MAF, etc. I didn't find anything obvious (although I'm probably below a novice with SDS), I cleared the stored code. I suspect this is an intermittent issue that trips the CEL when something is just slightly out of spec. Seems odd that it is only on Bank 2. I would assume that it if was the MAF, I would be getting lean codes for BOTH banks. Since it is only on Bank 2, I would assume that it is after the MAF and not related to the new MAF, but I would have thought I would have gotten this code BEFORE replacing the MAF??? Could the MAF be bad, and only tripping CEL on Bank 2?
Any suggestions or advice of what to check from here would be appreciated. I have cleared the CEL, and it is off for now, but I expect it to return in the next few days...
THANKS
Lee
Originally, I had no codes, but the throttle response was delayed. I cleaned the MAF and this improved slightly. I replaced the MAF (Bosch 0280217810 from Amazon) and throttle response was great, and I thought the problem was solved. However, about a week later, I got the stored P0174 code. I couldn't find any loose vacuum hoses, and checked that MAF was properly seated. I cleared the code and everything was fine, but P0174 came back after about a week. Everything is running fine with no other symptoms other than the CEL.
I have SDS, and I could test MAF, etc. I didn't find anything obvious (although I'm probably below a novice with SDS), I cleared the stored code. I suspect this is an intermittent issue that trips the CEL when something is just slightly out of spec. Seems odd that it is only on Bank 2. I would assume that it if was the MAF, I would be getting lean codes for BOTH banks. Since it is only on Bank 2, I would assume that it is after the MAF and not related to the new MAF, but I would have thought I would have gotten this code BEFORE replacing the MAF??? Could the MAF be bad, and only tripping CEL on Bank 2?
Any suggestions or advice of what to check from here would be appreciated. I have cleared the CEL, and it is off for now, but I expect it to return in the next few days...
THANKS
Lee
