JonScotti

HELP! I just bought a 99 GS4 with 79K on it. Looks like it has an intake and exhaust on it, as well as a decent looking bodykit. Anyway, the day I test drove it, it would hesitate when first driving. The dealer replaced the throttle position sensor, or so he said. A couple days ago, I was driving REAL hard, and the CEL and VSC and VSC off lite come on, and I lose all throttle. The bottom 1/8" of the gas petal worked. I brought it back to the deal under warranty, he cleaned the throttle body and MAF sensor. Everything was great, now same problem. I only had the car for a week and LOVE it already, but should I take this back under lemon law on give 'em another chance to fix it? What should I tell them to look at? The mechanic at the dealership doesn't look to knowledgable? Please help..thanks in advance fellas...
Scott

T.K.O.

ooo boy. i wish i could help. someone here will! i would give them one more shot at fixin it if you really love it.. (umm gs.. im sure u love it!) but dont put up with it if its faulty.. itll cost u way more to fix it in the long run then it will for u to get ur own exhaust, intake, and a real nice body kit on a stock one w/o any problems

my .02

sleeper408

iTrader: (6)

If they really did fix the TPS problem, then it might me the accelerator pedal position sensor instead.

JellyBean

What he said. And to make it absolutely clear, the TPS and the APPS are different things.

GWELEX

Those exact symptons happened to me once and it was severe leak at one of the seals on the intake. Could be when he cleaned the throttle plate he didn't get all of the clamps tightened down on the intake. Worth a look and very easy fix.

JonScotti

Thanks guys... Off to the mechanic to check APPS and intake seals. Quite a statement to how fun these cars are. If any of my other vechiles had acted up twice in the first week of ownership I wouldn't even consider keepin it. I think I'll just pony up the $1500 for the extended warranty and hope for the best. This car rox !! Thanks again for the help...

tmf2004

iTrader: (15)

Welcome to CL.. Lets see that GS..

JonScotti

Here is it... Couple of bumps & bruises, but WAY better than average for a 99. Plus one of my best friends' owns a body shop.... Let me know whachu think.....

gserep1

The 1999 GS 400 does not have APPS (accelerator pedal position sensor). That is for 2001 and above GS's. The 98-2000 GS's have an actual cable from the accelerator pedal to move the throttle body plate. The newer GS's have an electric motor on the throttle body, and the APPS resistor on the accelerator pedal signals the computer when pressed, and then the computer sends a signal to the electric motor on the throttle body to open the throttle plate as required.

My 1999 GS 400 is bone stock, and I don't know what your aftermarket intake is doing to affect the check engine light, but I suspect bad intake seals. If they did not replace the gaskets with new ones when replacing the intake, then that would be a big possibility. Also check the intake gasket near the throttle plate out front. It could be leaking. That would set a code tha would cause all 3 lights you mentioned to come on.

I have never had a problem, but the original owner of my car had a complete throttle body replaced 1 year before I took delivery in 2004.

I would suggest you get the code (s) read to see what the problem is while the lights are on. You may still have a bad TPS near the throttle body.

Get it checked out. You can get the codes read at AUTOZONE for free or very reasonable price.

olddog

iTrader: (2)

why don't you get a stock intake and put it on to see how it works.
sometimes aftermarket intakes can set lights off and malfunctions in car cos of the different setting.
good luck

GSteg

iTrader: (15)

the 98-00 has an electric motor on the throttle body. Pulling on the cable wont open the throttle plate by itself. I've checked

LEXUS_KID

iTrader: (4)

WELCOME JonScotti

JonScotti

The problem seemed to fix itself until today.. right after I had my new stereo put in (of course).. but I had the codes read and it says Accelerator Pedal Position Sensor. My car is a 99, and the post above says my car doesn't have a APPS... I was going to call tommorrow to order a APPS, but don't wanna sound like a jerkoff if the car doesn't even have one. Are you sure the car does NOT have a APPS, if so, how come the code says so?

GSteg

iTrader: (15)

Our car does have an APPS contrary to the post above. We have it because our throttle system is not fully drive-by-throttle cable like the conventional throttles found in other cars. If you have taken part your your intake and try to pull on the throttle cable, you'll notice that the cable moves the electric motor on the throttle body, but the throttle plate does not move at all. When you step on the pedal, the throttle cable turns a shaft. The APPS senses the position and gives off a certain voltage to the ECU, depending on how much pedal travel there is.

The Accelerator Pedal Position Sensor is located to the left of the Throttle Position Sensor if you're standing in front of the car looking into the engine bay.

Spyder78

iTrader: (7)

whats the difference? I would call just to verify. But I am pretty sure that your gs still has a apps since that is the code its displaying