View Full Version : P0171: System too lean


RX8 Brunei
12-10-2005, 01:46 AM
:rofl: need opinion on this.

Refering to my previous post http://www.rx8club.com/showthread.php?t=75540. My 8 recently had starting problem (hard start) & engine stalls at idle.

This is what i found out by retreiving DTC with sCANalyzer : Pending P0171 i.e. system too lean. Attached below is DTC Table. This might give me idea of what's going on with my 8.

Since i've reset ECU & KAM long ago, so there's no CEL/MIL been stored in PCM. I retrieve this "P0171" code (1 drive cycle) while the car is station & engine start by the help of alcohol.

I need to drive the car by next week (Drive Mode), so that i can throw CEL blinking & flashing all the way. Then i'll know what DTC appear when i retrieve it.

Stay tune & wish me luck :squint: .

swoope
12-10-2005, 03:40 AM
i would pull out the maf sensor and clean it with electronics cleaner. easy to do. if i recall your car was flooded.

it is a start.

beers

Rasputin
12-10-2005, 08:31 AM
Can you post the freeze frame data (all the engine parameters at which the error happens) given by the sCANalyser?

Fabrice

r0tor
12-10-2005, 04:14 PM
i would pull out the maf sensor and clean it with electronics cleaner. easy to do. if i recall your car was flooded.

it is a start.

beers

i 2nd that

RX8 Brunei
12-11-2005, 08:32 AM
already done deflooding procedure more than 20 times.

RX8 Brunei
12-11-2005, 08:36 AM
Can you post the freeze frame data (all the engine parameters at which the error happens) given by the sCANalyser?

Fabrice

No freeze frame data appears. That's why i've to follow the "drive mode" procedure so that CEL/MIL appear. Give me few more days. I'll update sooner or later.

RX8 Brunei
12-11-2005, 08:40 AM
i would pull out the maf sensor and clean it with electronics cleaner. easy to do. if i recall your car was flooded.

it is a start.

beers

i've done it using contact cleaner. the result still the same. the only way is to swap with my friend's MAF sensor. i'll proceed on that later after i get those CEL.

crossbow
12-11-2005, 11:23 AM
Are you running with an intake? The p0171 cel is one of the most common cel's seen in the 6 for those running intakes.

RX8 Brunei
12-11-2005, 10:05 PM
Are you running with an intake? The p0171 cel is one of the most common cel's seen in the 6 for those running intakes.

yup. be4 i was using HKS racing suction kit. used it around 22,000km, now back to stock. i'm not sure if the problem comes from MAF sensor.

j9fd3s
12-11-2005, 11:17 PM
Are you running with an intake? The p0171 cel is one of the most common cel's seen in the 6 for those running intakes.

yep, put the factory intake on and the cel will go away....

RX8 Brunei
12-16-2005, 01:02 AM
yep, put the factory intake on and the cel will go away....

Done that. Last night i tried to start the engine, to see if there's new DTC occur. Juz like a member said that P0171 only appear in 1st drive cycle. After i clear the DTC off, no DTC after retrieve.

My friend said that JDM ECU originally set the AF slightly lean. AF will be more leaner when replace the stock airbox to aftermarket intakes. Can anybody make me clear about this?

Last night, i don't manage to drive the car (gas tank nearly empty). But i'll drive it tonite.

RX8 Brunei
12-16-2005, 01:10 AM
About this AF thingy.... i have in my mind about TurboXS DTEC FC. Since there's no ECU flash at the dealer, i'll go for this stuff when it's confirm that no parts/sensors are malfunction. Juz my thought. Any recommendation?

Hymee
12-17-2005, 08:24 PM
Any exhaust changes - eg O2 foolers, CAT replacment/removal???

Cheers,
Hymee.

Im_DANomite
12-17-2005, 11:40 PM
you're getting un-metered air into the engine. i'd check vacuum lines, loose intake connections, etc. spray some brake clean on suspected areas and see if the rpm or engine changes its speed. i'd start by doing that first. no leaks found means it's something electrical.

RX8 Brunei
12-19-2005, 11:50 PM
Any exhaust changes - eg O2 foolers, CAT replacment/removal???

Cheers,
Hymee.

I'm replacing the CAT converter pipe (already dead) with a custom CATless direct pipe. It's still there coz i don't plan to change it back to stock & very pricey to get new CAT. I didn't install any o2 foolers. Thanks for the feedback Hymee.

RX8 Brunei
12-19-2005, 11:54 PM
you're getting un-metered air into the engine. i'd check vacuum lines, loose intake connections, etc. spray some brake clean on suspected areas and see if the rpm or engine changes its speed. i'd start by doing that first. no leaks found means it's something electrical.

Thanks bro. Will do it l8r on.

RX8 Brunei
12-20-2005, 12:12 AM
OMG. I 4got to mention that i've test drive the car last friday night. Sadly i don't get any CEL coz i only manage to drive it 1.5km only. That night the road was very congested/rainy condition, so i give up. As u all know that i had to press the accelerator pedal constantly to make the engine rev at least 2,000rpm (engine will stall if rpm drop below 2000rpm). I'll try to drive the car at midnight on this weekend. Distance target 15-30km at highway. Hopefully i'll get CEL from this upcoming attempt.

Hymee
12-20-2005, 01:24 AM
I would have thought it would already have a CEL if it is running that poorly!

Cheers,
Hymee.

RX8 Brunei
12-20-2005, 11:32 PM
I would have thought it would already have a CEL if it is running that poorly!

Cheers,
Hymee.

Yeah i thought so. It's really weird.

RX8 Brunei
12-21-2005, 12:46 AM
4got to take a pic of sCANalyzer monitoring the details of my 8. All i remember is whether the MAF or AFR is more than 15.0+, the highest is 19+. And that's too damn lean am i right?

RX8 Brunei
01-02-2006, 09:43 PM
Confirm MAF sensor malfunction.

Hymee
01-02-2006, 09:59 PM
So do you have a mate with an RX-8 you can try swapping the MAF sensor with? Simple to do - undo 2 screws and a connector. If that fixes it then you can order one from spare parts. Don't forget when it is all fixed, you might have to reset the CEL (or you didn't get one?? - weird) using your sCANalyser.

KJ238
01-02-2006, 10:21 PM
He's gonna do that today... He practically knows every rx-8 in this country.....

I just hope that it is as simple as a MAF problem.... Good luck bro

yiksing
01-02-2006, 10:44 PM
Looks like a turn of luck for you eh RX8_Brunei, good luck

tems900
01-03-2006, 07:43 AM
Confirm MAF sensor malfunction.

can buy e MAF in S'pore for SG$252 include tax, just replace it today. Have driven the car for 2yrs , 37000Km, having problem starting e car since 3 weeks ago but no CEL, had tried all the deflooding procedure, change battery, new spark plug, put back e OEM CAT midpipe, now MAF & i hope it work, if not i need to remove the Trust CAI & put back e OEM airbox, if all e change still don't help, i need to sent my ECU back to KnightSport for retune. :mad:

RX8 Brunei
01-03-2006, 09:11 PM
So do you have a mate with an RX-8 you can try swapping the MAF sensor with? Simple to do - undo 2 screws and a connector. If that fixes it then you can order one from spare parts. Don't forget when it is all fixed, you might have to reset the CEL (or you didn't get one?? - weird) using your sCANalyser.

I've swapped the MAF sensor from other AT owner but still hard to start. I thought that ECU has cut the fuel from injecting to the rotors when i had this problem from day one.

I remember that the 1st time i'm doing deflooding, i don't see any oil/fuel drains from the sparkplug holes (front rotor), even the plugs (trailing & leading) are clean (no oil).

By common sense, no fuel injected to the rotor (could be fuel-cut by ECU) won't fire up the engine. Give me some light please. I'm a newbie LOL. I remember there's a link that shows how rotary engine works.

RX8 Brunei
01-03-2006, 09:12 PM
can buy e MAF in S'pore for SG$252 include tax, just replace it today. Have driven the car for 2yrs , 37000Km, having problem starting e car since 3 weeks ago but no CEL, had tried all the deflooding procedure, change battery, new spark plug, put back e OEM CAT midpipe, now MAF & i hope it work, if not i need to remove the Trust CAI & put back e OEM airbox, if all e change still don't help, i need to sent my ECU back to KnightSport for retune. :mad:

How much retune ECU will cost?

RX8 Brunei
01-03-2006, 09:16 PM
He's gonna do that today... He practically knows every rx-8 in this country.....

I just hope that it is as simple as a MAF problem.... Good luck bro

Dunno yet bro. I've to wait for MAF sensor for 6MT to arrive, haven't order it yet. U wanna lend me ur MAF sensor meh?? LOL

RX8 Brunei
01-03-2006, 09:19 PM
anybody wanna sell their used OEM CATmidpipe for B$100?? hehehe :cwm27: