Engin management light stays on

Steve Allison

• 5569 Answers
• Posted on Jul 20, 2008

SOURCE: Engine Management Light

If you have an exhaust leak before or after the catalytic convertor, then the response of the of the sensor could be slowed.

An excerpt from Wikipedia:
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Location of the probe in a system
The probe is typically screwed into a tapped hole in the exhaust, located after the branch manifold of the exhaust system combines, and before the catalytic converter. New vehicles are required to have a sensor before and after the exhaust catalyst to meet U.S. regulations requiring that all emissions components be monitored for failure. Pre and post-catalyst signals are monitored to determine catalyst efficiency. Additionally, some catalyst systems require brief cycles of lean (oxygen-containing) gas to load the catalyst and promote additional oxidation reduction of undesirable exhaust components.
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It's a good article about the two-sensor system and oxygen sensors in general and is available here:

http://en.wikipedia.org/wiki/Oxygen_sensor

SOURCE: Engine management light on

P0350 Hyundai Ignition Coil Primary/Secondary Circuit

SOURCE: code p1128 weak mixture lose

Go to www.hmaservice.com and register your vehicle by VIN #..
you'll then have access to wiring diagrams, shop manuals,
service bulletins, illustrations, etc. To diagnose a 2000 or 2001 1.5L Accent Diagnostic Trouble Code (DTC) P1128 (FUEL SYSTEM LEAN -- PART LOAD), check the following:

• Check the intake system for air leaks.
• Check that the Mass Air Flow (MAF) Sensor (P/N 28164-22610) operation meets the specifications listed below. If the MAF sensor output is significantly lower than the reference value (10% or more), then replace the MAF sensor.

WITH MANUAL TRANSMISSION

Table 3: Using the Hi-Scan Pro in the Hyundai Diagnostic Menus Current Data Screen TPS (%) 0
2.4
3.9
5.9
MAF (kg/h) 9.5
19.4
28.8
43
RPM IDLE
2000
3000
4000
Table 4: Using the Hi-Scan Pro in the OBD-II Menus Current Data Screen TPS (%) 0
2.4
3.9
5.9
MAF (g/h) 2.5
5.5
8
12
RPM IDLE
2000
3000
4000