Starting on Thursday morning, the Forester started throwing P0171 codes while driving at highway speed. I cleared it on Thursday (using "Torque"), and it threw again on Friday morning while driving to Biwabik, I didn't clear it again until this morning. The commute was slow this morning, so I didn't really get up to speed. I'm not feeling any drivability issues. I'm just learning my way around the Torque app, so I haven't gotten as far as analyzing the logs. Specifics: 2004 Forester XT 5MT ~89,750 miles No engine/intake/exhaust modifications just changed spark plugs last weekend (2/23), and drove it every day last week. Thoughts?
http://engine-codes.com/p0171_subaru.html No mods and spark plugs were the recent change. Did you gap them properly? That's all I can think of really.
I guess I'm going to have to check them. That will be Sunday at the earliest. Cleaning the MAF is still on the docket, per another thread here. That description has me thinking I should check that darn after-MAF hose. It's a royal pain to get on, I need to check that the clamps are tight, and that I didn't manage to damage it. Luckily I have a spare! I don't have a spare MAF, though. Here's a nice bit of plug information: http://www.subaruforester.org/vbulletin/43242-post10.html
Some people (however not all) reported that changing out the front O2 sensor with an OEM one worked for them. And one (me) has reported that a NF tune also takes care of this.
I'm going to start with cleaning the MAF, and check for obvious sources of "false air" (aka intake leaks). An NF tune certainly isn't out of the question!
On my way to get NF tune, my car threw a code. Tune. Code gone never to return Me: my car threw a code on my way here Nuke: your car needs a tune
His car is stock. Getting it tuned isn't going to fix the problem that is causing the CEL for "system too lean." In fact, I would suggest fixing that CEL problem BEFORE getting it tuned.
Agree. Guess I read over that first post a little fast. My car had light mods not to mention an Accessport that was running an off the shelf map.
No new codes. The only thing I found is that I forgot to re-install the very last bit of the snorkus that bolts down over the passenger headlight. I checked the hose clamps on the after-MAF hose, and, since they are easy to get to, the two between the I/C and the throttle body. Everything is tight. I'll update if anything new happens.
