Obd 171 - too lean. what does this mean and how

About 259,000 results (0.64 seconds) Search Results

obd ii - 'Check Engine' code P0171 System Too Lean - Is it ...

mechanics.stackexchange.com/.../check-engine-code-p0171-system-too-l...
Feb 11, 2014 - 'Check Engine' code P0171 System Too Lean - Is it safe to drive? ... My question is: is it okay to drive my car while it shows these codes? ... This will cause you to get increasingly worse fuel mileage. ... I am going to defer to your expertise, but I just want to ask if you've considered that lean-running engines ...

P0171 and P0174 - OBD-II Trouble Codes - RepairPal

repairpal.com > Encyclopedia > OBD II Codes
Definition of error code P0171 and P0174 - System too Lean (Bank 1 and Bank 2). ...Before we get into the main causes of P0171, let's explore why this code matters. ..."Lean" running cars and light trucks are highly polluting vehicles. Most of ...

Mazda tribute codes p0171 - Cars & Trucks 'Cars & Trucks

www.faqqq.com/.../mazda-tribute-codes-p0171-cars-trucks-cars-trucks-6...
Question Product: Cars & Trucks Question Details: Mazda tribute codes p0171 ... I am getting the following (4) codes in a 2003 Mazda Protege5 engine: P0090 ...

P0171 Code thrown while idle - Toyota Nation Forum : Toyota Car ...

www.toyotanation.com > ... > Yaris/Scion iA, Vitz and Echo Forum

According to the page I found at Toyota, it's a "Random cylinder mis-fire" - meaning it is not happening consistently. Here is the site for the code 300: http://engine-codes.com/p0300_toyota.html.

Also according to the same site, on this different link, is your code for the 171 which states that it is a " fuel mixture system being lean on bank one" of your engine. The site goes on in substantial detail in both cases to tell you what the cause could be and how to fix them. Best of luck with it, hope you can do it yourself. Here is the other link: http://engine-codes.com/p0171_toyota.html

Code 171 and 174 are for bank 1 and 2 running too lean. The engine has compensated as rich as it can go, and it is still to lean. This does not necessarily mean your mixture is bad, but something (a sensor) is telling the ECM to correct lean. The oxygen sensors alert the ECM to how lean/rich the exhaust is, and then the ECM trips a code. Maybe you have a bad oxy. sensor, but since there are 4 of them (2 per bank), I don't think they could all go at once.

Google your codes & then diagnose the
system & items related to the codes

Type: OBD Code PO 171 --or whatever the codes are

If you have Oxygen Sensor Codes, it is most likely the upstream sensors have failed, because you did not know they get replaced as preventative maintenance at 100,000 or when they fail, if that is how you take car of your vehicles

The compression is not the problem, it's possible that you just got a defective coil or there may be an intermittent problem with the #4 fuel injector, the P0171 will come back when there is a misfire once the misfire is fixed the P0171 will stay gone, a fuel injector seems logical since if it's sticking it will drive the system lean which is what the 171 code is for.

Under certain conditions customers may experience a MIL "ON" condition with DTC P1349 indicating a variable valve timing (VVTi) malfunction. In some cases, the cause of this DTC may be the VVTi actuator.

In general P1349 is a misfire or ignition issue under most general OBD-II - but Toyota spec'd OBD-II has it as a VVT malfunction. Unfortunantly - hard to tell which it is. Might be the ignition timing set too advanced (VVT-i issue) or low fuel pressure (bad or clogged injector, bad or low flowing fuel pump/regulator). An emissions test could tell you which one it is. If you want to try a quick fix on your own, I'd start with the basics, change the spark plugs, air filter, and maybe the pcv valve, all these are cheap and easy. Other things could cause the problem though, so if the quick fixes don't work, I'd lean toward the injectors.

Seafoam and other additives are very good solvents that can help clean the injectors - but may not be strong enough to clean off these injectors. Injector cleaning services generally don't work that well - best way is to have these cleaned ultrasonically or replaced (very costly).

171 system to lean bank one, 174 to lean bank 2, 300 multiple miss fire,316 crank sensor defective. Does it run rough? Replace crank sensor first.

go to any kragen or autozone parts store, they will run the test for trouble code that turned light on for free, tell them u want an OBD 2 trouble code test, then post the code here.

Symptoms of a faulty Camshaft Position Sensor can include hard starting (or no starting), rough running/misfiring and/or loss of power.

Code 340 COULD be caused solely by a faulty Camshaft Position Sensor. However, this code refers to the entire circuit. So, replacing the sensor may not fix the issue. The problem could lie in any part of the circuit - the sensor itself, the wiring, or the PCM.

Codes 171 and 174 typically appear together. They are caused by the 02 sensors reading too much air (lean) in the exhaust. In most cases, simply cleaning the MAF sensor does the trick. I typically take it off and spray it with electronics or brake cleaner. Just make sure it dries before reinstalling. If this doesn't eliminate the codes, inspect all vacuum and PCV hoses, check for a dirty fuel filter and ensure the furl pressure is within limits.

For clarification, the first trip to the shop your car showed codes 402, 732, 733, 171 and 174. After changing the DPFE/EGR, did ALL those codes go away and now only codes 340, 171 and 174 exist? Or do you have the second set of codes in addition to the first codes?

Po171 is a lean condition on bank one ( only one) o2 sensor in front of the catalytic converter. Could be a mass air also could be a vacuum leak. or a bad o2 so dont jump to expersive parts unless you have another car to swap stuff around