Hyundai Forum: Hyundai Performance Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter · #1 ·
I have an '00 LC 1.5 SOHC, with the check engine light on. The code is p1128, and reads "fuel trim lean under load". The car stutters when I accelerate from a light or when I give it some gas from second gear. At times the MIL light has flashed. I have read that it might be a faulty MAF sensor, leaky injector or a leak around the intake tube before the throttle. Another thing that I have read is to disconnect the MAF sensor and drive.

Anybody with any suggestions or have the same issue?

Thanks
 

·
Registered
Joined
·
260 Posts
I have an '00 LC 1.5 SOHC, with the check engine light on. The code is p1128, and reads "fuel trim lean under load". The car stutters when I accelerate from a light or when I give it some gas from second gear. At times the MIL light has flashed. I have read that it might be a faulty MAF sensor, leaky injector or a leak around the intake tube before the throttle. Another thing that I have read is to disconnect the MAF sensor and drive.

Anybody with any suggestions or have the same issue?

Thanks
I had the same problem in my old LC. i changed the spark plugs and wires. There was an oil leak because of the gasket and i replaced that too.
 

·
Registered
Joined
·
30 Posts
There is two things that can be problem… front O2 sensor or MAF sensor?
Code P1128 is turned on when front O2 sensor have wrong readings but it doesn’t have to be problem in O2 sensor…
MAF sensor can work strange and measure that les O2 is coming in the engine so because of that the mixture becomes to lean…

Can you see the MAF readings on your scan tool that you have? :)
 

·
Banned
Joined
·
1,112 Posts
check the plugs first cuz if the car misfires of course it will throw off the fuel air mixture which then would set off a code for a lean or rich condition. my car missed alot and had 3 codes and i replaced the injectors and checked everything else out and it didnt help. But then i checked the plugs and one new $10.00 NGK plug had a crack in the insulater..... i put back in my old bosch's and all is well.
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #6 ·
Thanks for the help. Since new, I've been using the NGK plugs from the dealer. I guess I can try the Bosch.
 

·
Registered
Joined
·
30 Posts
If sparkplugs or cables are problem then scan tool would turn on other eror code like “misfire detected on cylinder NO.3” of “random misfire detected”…

Cables and spark plugs are not lot of expanse so they can be changed any way… but I don’t think that they will solve problem.
 

·
Registered
Joined
·
53 Posts
New MAF sensor, replace both of the oxygen sensors if your car has to (or only do the one if you only have one), Spark plugs, Leads, Coilpacks... How much mileage have you done with it so far???

Cheers Ryan
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #14 ·
Yes I have the MAF info. At idle the airflow should be 2.5 g/h, the reading was 1.75 g/h. At 2000 RPM the reading should be 5.5 g/h, but the reading was 4.5 g/h.
 
1 - 17 of 17 Posts
Top