So i replaced the egr valve however, my transmission will not stay in 4th gear. Anytime you turn the car off and restart, it will go into 4th no problem, but after 5 to 10 mins it comes out of 4th and my live data shows 4th gear as being commanded off.

What gives? Very annoying to waste my gas like this... no cel.

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93 Buick Park Avenue
09 Pontiac Vibe AWD
01 Pontiac Sunfire GTX
84 Chevrolet Citation

I think you need a special scan tool to see trans codes. I'm guessing the EGR valve might be unrelated and it's coincidence. Maybe the 4th gear hub is close to wearing out.

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-Car Guy Carl
"Penelope" - 2003 SLE - 247k Miles
"Sydney" - 2000 Honda S2000 - 98k miles

Mines odd as well it needs one drive cycle in thr morning. Thr rest of the day itll hit 4th everytime!

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1995 se
128,101
custom FWI
rt-95 rims look kinda like crosslaces
6000k hids
f- body muffler dual output
96-99 headlight conversion, clear markers

That is likely normal shifting with a cold engine. Most cars will not shift to overdrive to speed up the time to reach operating temperature, it is suppose to reduce emissions and help gas mileage.

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2004 Bonneville SE 151,xxx- 20% tint all around, 5% tint bar on windshield | 4500k DDM HID low | De-badged | Hardwired Passport 9500ix | FWI(inter-cooler piping) | FE2 Rear Sway Bar | Solid Motor Mount | 180* Stat | Firm Shift Kit



- '92 Bonneville SE - '85 Grand Am - '73 Catalina - '67 Catalina
- '87 Bonneville SE - '82 6000 - '78 Catalina [/color]

I realize most cars do this but i randomly started doing it

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1995 se
128,101
custom FWI
rt-95 rims look kinda like crosslaces
6000k hids
f- body muffler dual output
96-99 headlight conversion, clear markers

Egr valve has nothing to do with it.And Nos4blood70 is right about the scan tool. Had mine checked and I must have a worn hud shaft. No 4th gear on my car.

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What does it profit a man to gain the whole world and lose his soul.

If it is commanding a downshift, you may want to scan all other live data to see if you can identify an issue. TPS comes to mind, maybe a temperature sensor too

Also, they are correct, it does behave differently when cold, but i believe the magic number is 70*, and it just doesnt lock the TCC

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~Randall~


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place

Hard parts failure would usually mean no 4th gear ever. For some reason the pcm thinks it needs to stay in 3rd gear if it doesn't command 4th gear.

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Boost addict


The Fleet:
'93 SSEi - Twincharged + manual Build thread
'97 Camaro - Top swap
'05 STS - V8, AWD, her DD
'92 Trofeo - Fair weather DD
'99 Montana - top swap 3800
'04 Sierra 2500HD - LLY Duramax

Current project:
Something cool, trust me.

Upcoming projects:
'92 Bonneville SSE
'87 LeSabre T-type
'67 LeSabre

Gone to greener pastures:
'84 Sierra Classic - Twin turbo 3800
'97 LeSabre - Top swap

RIP:
'86 LeSabre - pictures
'93 SE - L67

Ok thanks guys, ill start checking sensors and data and see what its doing!

_________________
1995 se
128,101
custom FWI
rt-95 rims look kinda like crosslaces
6000k hids
f- body muffler dual output
96-99 headlight conversion, clear markers

A good idea.

Heres a funny thing, when I am cruising at 100 kph, the tranny in third, my rpms are at roughly 2800. If I let off the gas to coast down a hill, the tach dips to 1000 rpms and jumps back up immediatly. Wierd...

What should the tps be showing at cruise?

Its funny because when the car is cold, and just starting out, I have fourth gear and tcc lock. But both disappear after 5 to 10 mins. Would the pcm keep the tranny out of 4th because the tcc doesn't lock? I can live without tcc, but no fourth gear kills my gas mileage big time!

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93 Buick Park Avenue
09 Pontiac Vibe AWD
01 Pontiac Sunfire GTX
84 Chevrolet Citation

Looking on Identifix, someone stated that 4th gear is inhibited if the TCC does not work. Makes sense as to the way the car has been acting. Makes no sense as to why some engineering brainiac would design a car to waste gas when a simple solonoid goes bad!? At 100, the car is fine at 2000 rpms, but lose 4th gear and it surges to 2500-2800 rpms!!

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93 Buick Park Avenue
09 Pontiac Vibe AWD
01 Pontiac Sunfire GTX
84 Chevrolet Citation