1999 Buick Park Ave Ultra Service Engine Light Code #P0742

A bad injector will cause a misfire. You need to replace it and see if the issue is corrected.

Clean your IAC.

FYI, you also could have a VACUUM LEAK

The Gen II 3800 Engines have a HORRIBLE ISSUE with the INTAKE. They are made from Plastic and Warp. Waiting for the Engine to Get Hydro Locked (Coolant in the Cylinders)

The code indicates the TPS is still bad and the code is usually right, but it could be a wiring issue at the TPS connector or less likely a computer issue.
To test the TPS circuit, you need to check voltage and ground from the ECM - 5v is the normal reading between the ECM reference circuit and the ECM ground circuit at the TPS connector. Checking the TPS signal circuit to the ECM requires monitoring the TPS signal on a scan tool while jumping the 5v reference and the signal circuits. The TPS reading should go from high when the circuit is jumpered to low when the jumper is removed.

If the light is on the engine computer will have a trouble code or codes, which may help you towards solving the problem. Have the computer scanned for the codes. Go from there. Good luck.

On this website you find ruse box diagram and description for Buick Park Avenue (1997 and 1999)

Buick Park Avenue 1996 1997 fuse box diagram CARKNOWLEDGE

http://www.carknowledge.info/buick-park-avenue-1998-1999-fuse-box-diagram

P0742 Torque Converter Clutch Circuit Stuck On

TSB #00-07-30-007A: Whine Noise in Park or Neutral, Service Engine Soon or Service Vehicle Soon Lamp Illuminates (Replace Drive Sprocket Support Bearing) - (Jan 30, 2002)
Subject: Whine Noise In Park Or Neutral, Service Engine Soon or Service Vehicle Soon Lamp Illuminates (Replace Drive Sprocket Support Bearing)

Models:
1999-2000 Buick LeSabre, Park Avenue/Ultra, Regal, Riviera
1999-2000 Chevrolet Lumina, Monte Carlo, Venture
2000 Chevrolet Impala
1999 Oldsmobile Eighty Eight
1999-2000 Oldsmobile Intrigue, Silhouette
1999-2000 Pontiac Bonneville, Grand Prix, Montana with 3.4L, 3.5L or 3.8L Engine (VINs E, H, K, 1 -- RPOs LA1, LX5, L36, L67)
and Hydra-Matic 4T65-E Transaxle/Transmission (RPOs MN3, MN7, M15)

This bulletin is being revised to add the Chevrolet Impala to the models affected. Please discard Corporate Bulletin Number 00-07-30-007 (Section 07 - Transmission/Transaxle).

Condition

Object



(1) Transmission ID Location
(2) SRTA Tag Location
(3) Hydra-Matic 4T65-E SRTA Tag
(4) Model Year (9 = 1999)
(5) Control Number
(6) Transmission
(7) Serial Number
(8) Julian Date
(9) Calendar Year (9 = 1999)
(10) Model
(11) Hydra-Matic 4T65-E ID Tag
(12) Model Year (9 = 1999)
(13) Line Built (1 = Line 1; 2 = Line 2; 3 = Line 3; 4 = Line 4)
(14) Transmission
(15) Julian Date
(16) Shift Built (A = First Shift; B = Second Shift; C = Third Shift)
(17) Model
(18) Serial Number in Base Code 31
(19) W = Warren Plant
(20) Hydra-Matic 4T65-E
(21) Model

Some owners of the above models equipped with a Hydra-Matic 4T65-E transaxle with a Julian Date prior to 0045 may comment on a whine noise in PARK and/or NEUTRAL or a Service Engine Soon or Service Vehicle Soon lamp that is illuminated. Upon investigation, a DTC P0741 or P0742 may be found.

Cause:
The above condition may be due to drive sprocket support bearing fluting and/or bearing failure.

Correction:
Replace the drive sprocket support bearing. Inspect the channel plate and drive sprocket for any abnormal wear, Turbine shaft for cut seals and/or nicks, and chain for excessive play due to failed bearings.

Important:
When installing the new bearing, the part number MUST be visible (facing upward). Before installing the drive sprocket, lubricate the bearing assembly with J 36850 assembly lubricant.

Refer to the 4T65-E Unit Repair Section for the installation procedure.

Service Part Information:
Part Number: 24214158
Description: Drive Sprocket Support Bearing


Parts are currently available from GMSPO.


Its possible that you can use a voltmeter to test for power and ground at the TCC solenoid connector and also resistance across the solenoid. The scan tool is helpful in pulling the codes, commanding the TCC on and off and monitoring the state of command while driving.

Hope help with this (remem,ber comment and rated this).

you have a paracitic load on the engine, even if the light has gone off the code will still be stored in the computer until someone clears it, get it read out and it will give you a pretty good idea of what set it off

It is part of the ABS wheel sensors.So yes it is part of the ABS system.

This is a problem in the circuit that controls the warning light on your dash. I am not sure why you would have failed emissions for this, I would call your BMV and find out.

It sounds like one of the ignition wires is breaking down or possibly a coil. Get a squirt bottle of water and spray a mist on the plug wires and coil to see if a spark starts to jump out. Probably just a bad plug wire.