1999 GS300 Engine Code P0171
Thread Starter
Driver School Candidate
Joined: Aug 2020
Posts: 6
Likes: 0
From: CA
1999 GS300 Engine Code P0171
Hey yall, so '99 lexus gs300,
I recently installed an aftermarket intake on my car (got rid of stock air filter and intake). It's all been working great but I noticed the car was having a little difficulty accelerating from a dead stop (happened out of nowhere), nothing crazy but just slight hesitation, and then got a check engine light.
I scanned it and got the code P0171 Bank 1 Too Lean. I googled it already but I couldn't find any useful info. What could be some issues/solutions? If it helps, I recently had the code P1349 (OCV) and I replaced the OCV and the Check Engine Light had gone away. I double checked the vacuum lines connecting to the intake and they're all sturdy.
Could it be the silicone connector that connects the intake to the throttle body? I did have issue with the car turning off out of nowhere due to there being a bad connection, but after I tightened the hose clamps, I never had that issue again.
Is the car safe to drive?
Thanks in advance and sorry for the multiple questions.
I recently installed an aftermarket intake on my car (got rid of stock air filter and intake). It's all been working great but I noticed the car was having a little difficulty accelerating from a dead stop (happened out of nowhere), nothing crazy but just slight hesitation, and then got a check engine light.
I scanned it and got the code P0171 Bank 1 Too Lean. I googled it already but I couldn't find any useful info. What could be some issues/solutions? If it helps, I recently had the code P1349 (OCV) and I replaced the OCV and the Check Engine Light had gone away. I double checked the vacuum lines connecting to the intake and they're all sturdy.
Could it be the silicone connector that connects the intake to the throttle body? I did have issue with the car turning off out of nowhere due to there being a bad connection, but after I tightened the hose clamps, I never had that issue again.
Is the car safe to drive?
Thanks in advance and sorry for the multiple questions.
Pole Position
Joined: Nov 2018
Posts: 2,077
Likes: 576
From: CA
That is a lean code meaning there is more air entering the engine than there should be. Check the seal for the mass air flow sensor. That's what most people mess up when installing an intake. There is a leak somewhere between the MAF and throttle.
Racer
Joined: May 2017
Posts: 1,525
Likes: 354
From: Utah
About the most common cause of a lean code is a vacuum leak somewhere. If there is a slight hesitation when u snap the throttle, then u probably just have a vacuum hose that’s come off or cracked. U should be able to track it down by close observation and spending sone time inspecting the hoses and listening for a leak. If u can’t find anything, come back and search the boards, there are countless threads on this exact subject.
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