03 GS300 lag in first now stalling help
07-05-17, 02:35 PM
#1
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03 GS300 lag in first now stalling help
hi guys new to the forum and having car trouble and could use any advice or help. I have an 03 Lexus GS 300 it was at first just randomly lagging in first to accelerate or delayed to all of a sudden quick burst of speed and it has only been happening more often. Today the engine started going off while idling any help is greatly appreciate thanks in advance
07-05-17, 03:34 PM
#2
Scan it, I bet you're getting the codes P1120 and P1121. This sounds like an Accelerator Pedal Position Sensor problem (APPS) or maybe a TPS sensor issue and rarely a throttle control motor. Most of the time its the APPS. It can be dangerous if you're not a savvy vehicle operator. You'll loose power as you said (when the sensor malfunctions) and you'll naturally give it more gas with your foot to keep going, but when the sensor revives, it will see your foot down and you'll instantly take off at full throttle, thus the "burst of speed" you mentioned, that was just a minor incident. Do a search of the above codes and you'll see both mine and others' posts and recommendations on this as well as alternatives.
07-05-17, 05:11 PM
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Scan it, I bet you're getting the codes P1120 and P1121. This sounds like an Accelerator Pedal Position Sensor problem (APPS) or maybe a TPS sensor issue and rarely a throttle control motor. Most of the time its the APPS. It can be dangerous if you're not a savvy vehicle operator. You'll loose power as you said (when the sensor malfunctions) and you'll naturally give it more gas with your foot to keep going, but when the sensor revives, it will see your foot down and you'll instantly take off at full throttle, thus the "burst of speed" you mentioned, that was just a minor incident. Do a search of the above codes and you'll see both mine and others' posts and recommendations on this as well as alternatives.
07-05-17, 05:46 PM
#4
Yes it will make it stall because the sensor is not sending proper air intake. The unburnt gas smell can also be created due to incorrect air parameters causing the car to run rich. If it were an o2 sensor, it would run rough. Someone can chime in on the following, but I'm pretty sure an o2 sensor wouldnt cause the car to have a random delay then burst of speed.
Nonetheless, scan it. Have you not gotten a code yet?
Nonetheless, scan it. Have you not gotten a code yet?
07-05-17, 07:37 PM
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Yes it will make it stall because the sensor is not sending proper air intake. The unburnt gas smell can also be created due to incorrect air parameters causing the car to run rich. If it were an o2 sensor, it would run rough. Someone can chime in on the following, but I'm pretty sure an o2 sensor wouldnt cause the car to have a random delay then burst of speed.
Nonetheless, scan it. Have you not gotten a code yet?
Nonetheless, scan it. Have you not gotten a code yet?
07-07-17, 11:33 AM
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So I ended up getting codes p0102 / p0113 I cleaned the throttle added some fuel cleaner and cleaned the mass air flow sensor car started driving fine again. Left it running for a few minutes then the engine stopped again. Continues to die if left idle for too long. Any advice?!
07-07-17, 04:50 PM
#7
Man, I completely forgot about the MAF LoL I got all excited about the APPS 
Well, those codes as I'm sure you know are MAF and IAT, I'd lean towards the MAF since its before the IAT. Got any friends with GS's to swap it out? Or do a voltage test on it.
Well, those codes as I'm sure you know are MAF and IAT, I'd lean towards the MAF since its before the IAT. Got any friends with GS's to swap it out? Or do a voltage test on it.
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matthewlee
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