random downshifting?
 

so ive had the problem for awhile and its gotten worse. at first if i cruise at 70 mph it would randomly downshift then go back to about 2050-2100 rpms at 70. now it started doing it anywhere between 45-70+ mph. will downshift when im just cruising even does it with CC on. any one got ideas?

That used to happen when my IAT pigtail was all messed up. it would go into overdrive, then slip out like i was stepping on the gas. then do it again, and it was repetitive. I replaced the Pigtail (Mine was spliced, so this isn't your issue) However i would look into a new IAT sensor. any CEL?

no light. could i just cut the wires to the old one and attach a new one?

a guy on GAGT says its the torque converter. could that be it? no service lights are on in the car.

it COULD be.. but a TPS is cheaper. Throttle Position Sensor is pretty cheap and they do go bad. it will also screw things up cuz one minute it might think you have your boot in its mouth and the next you dont. try that first.

sleepy, got anyone you know with HP Tuners or something? Get a scan of it man, that will tell you right away whats up. Scan for IAT, IAC position, TPS, Commanded Gear, Input rpm and Output rpm. From there it should stick out like a sore thumb bud

thanks guys for the help, unfortunetly Ion has hpt still and at somepoint he will ship it back when he is done because i need it to tune the car for spray, speaking of mgt1 still wanna help me with that? :)

ill try changing the iat tonight. since i have extras around. but the tps isnt that old so i dont think ot would go out that quickly but who knows.. lol

no problem there. With HPT spray tuning is pretty easy man. Just make sure your nozzle is pre-IAT sensor

when you say pre-iat do you mean before the iat sensor?

No, It's the IAT Sensor, not the TPS. If it was the TPS sensor, it wouldnt make like you kept pushing the pedal, it would run like shit, burn massive amounts of fuel, and be hard to srart/keep running. Change the Intake Air Temperature Sensor. Simple as that.

Plus. Why the eff are you tuning for just spray? Talk about top end volcano action.

ill change it tomorrow. and because from tuning it i could get a little more power out of the car then just throwing it on there, and apparently the transmission will get destroyed because it cant handle the power and needs to be tuned to shift stiffer and change the iat -2 degrees iirc. and some other things plus i could do a little more tuning for the full exhaust and stuff haha. mmgt1 is the guy who told me basically all that iirc

:whistle:

I need to use it at the track for sure, it's rained out every effing time this week.. trying for Wednesday which means it'll be with you on Friday.

I think my friend had this on his at one point but he just took it the shop. I have no idea what it was or anything. When I get ready to drop in my supercharger sometime you think I could get ahold of to borrow your tuners sleepy?

ship the cd too please cause i got a new computer for tuning and dont have the program on here. :p thanks!


thats not up to me. the HPT is Ion's and me and him just share and trade off, i also paid him to borrow it. so if you really want to borrow the hpt ion is the man to ask. ;)

i think here soon if i the iat doesnt fix the problem then it will be takin to the mechanic to be fixed for a new torque converter, atleast i hope thats the problem, but im pretty sure it is.

I will get ahold of you guys when the time comes. Thanks.

I don't know if this will help or not, but my dad-in-law's Grand Am 3400 did the same thing and it ended up being a clogged CAT converter, just a thought

it might, but im sure there would be a svs light from the o2 picking up faulty readings? i have a 1.5-2 year old hi flow cat on there i dont think it would be clogged that quick? but idk on grand am gt alot of people are saying its the torque converter. i think some said they had the same issue. i just want the thing fixed. ill just see what my mech says and go from there but i wont be able to get to him for a couple days lol.

My torque converter went out on mine and I wasn't having the issue you were...I was getting a check engine light though. I hope for you that isn't your issue...it was a rather pricey repair...

hmm thats weird. ive got a few people saying they are sure its the TC. but yeah its going to be rather pricey. but gotta get it fixed. :(