Kaguilar35

Hello Clublexus! I recently purchased a 07 smoky granite mica is350 and already have a check light!. It's p0171 and p0174. Has anyone else run into this on their 350 at 59k? I read it could be a few things so i cleaned the maf sensor with maf cleaner but within 100 or so miles it came back. Could it be o2 sensors then? The car reads18.3mpg average. Doesnt hesitate, good power, not the smoothest idle tho. I live in seattle lots of hills and mostly city with a little hwy use. Should I change the maf out and reset or get a diagnostics from the stealership To see if it's the o2s. Any help would be much appreciated!

3sm1l

Do you have an aftermarket Intake?

I think you got a dirty MAF Sensor. Try to clean it good. Search here on the forums there's a DIY to clean it very well.

I used to have this problem and I cleaned my MAF two times and the problem still came back. After I cleaned it thoroughly it's been like 7 months and the problem hasn't come back

Kaguilar35

Thanks for responding so fast i love these forums! Everything is stock. I just got the car about 3 weeks ago. When I cleaned the maf I didn't see much grime or dirt come off of it. On 58k I would think it would have been dirtier by reading other posts on this issue. I think I'll check for a vacuum leak next. What do u guys think?

08is350x

Have you checked your gas cap? Also are you putting the right kind of gas? I got a check engine light once for running too lean and it was because I put gas from a cheap gas station even tho it was 93 octane. Since then I've put only gas from shell and haven't had a problem since.

Kaguilar35

I believe that code would be p0441. Premium only. I have a s2k that is premium also. Anybody else with ideas? Could carbon build up pop this code for running to lean?

Kaguilar35

The check engine light was from a vacuum leak on the intake box. Car is all good now!