RB25DET NEO Help

[AndyR34GTT]

Hello all,

My 98 GTT is having issues and I am stuck . the issues surprisingly happened after I washed my car but I am not sure if that is the reason for the issues . Initially there was no cel car started up no problem but seemed to have a misfire at idle and wouldn’t rev above 2k (limp mode ?) . I tried cleaning the AFM and still same issues then the idle got worse and worse . Now the car won’t hold an idle / start and threw codes 12 (afm) 17(abs?) and 46 (tms) . I pulled the coil packs and spark plugs to try to see if they were the issue and car looked to be running rich (black) and the coils (splitfire) all had resistance between 1.5 and 1.6 and cleaned the afm AGAIN so I put back everything back and codes 12 and 17 are gone now but 46 is still there ?
 

how do I correct the code ? Could my issues be from water in the cat from the car wash ? My dumb self also pulled the TPS without marking it so could that also be an issue for starting it? spark plugs are fairly new yet they were black when I pulled them (all of them) 
 

I plan to pull the cat tomorrow to take a look to see if it is clogged. 

also replaced fuel filter 

Side note, my coupler from TB to J pipe is cracking . Will a 2.5 silicon coupler work as a replacement for this old oem one ? 

any insight is appreciated 

[AndyR34GTT]

Upon further research I will also clean the iacv tomorrow 

[MspecR33_]

Make sure you set your TPS back to .46 volts with throttle closed and key in the on position (car off) then use multi metre and probe the positive up the back of your TPS plug, im not 100% sure which of the 3 wires is power on a NEO motor but on my S1 its the middle but just double check. 

as for the coupling in-between tb and j pipe, just take the old one off and take it with you to autobarn, supercheap whatever your go to is and match it up. Those places stock what you need  

[MspecR33_]

Just now, MspecR33_ said:

Make sure you set your TPS back to .46 volts with throttle closed and key in the on position (car off) then use multi metre and probe the positive up the back of your TPS plug, im not 100% sure which of the 3 wires is power on a NEO motor but on my S1 its the middle but just double check. 

as for the coupling in-between tb and j pipe, just take the old one off and take it with you to autobarn, supercheap whatever your go to is and match it up. Those places stock what you need  

hold on i just realised you're in the USA not Australia hahah, so in that case take the coupling to any automotive parts store you guys have over there instead hahah

[AndyR34GTT]

Thanks man ! I’ll calibrate the tps . This is the mechanical one though ? Same voltage right ?

[MspecR33_]

20 hours ago, AndyR34GTT said:

Thanks man ! I’ll calibrate the tps . This is the mechanical one though ? Same voltage right ?

Not sure what you mean by mechanical man but this is what im talking about, this is your TPS, and yeh 0.46V is what you’re after!

[AndyR34GTT]

Mine doesn’t have two plugs . It’s a 1998 rb25det Neo. I didn’t touch that sensor I removed the one in the back which is the mechanical tps which is measured by the throttle / pedal . 

 

 

TPS I bought

[MspecR33_]

8 hours ago, AndyR34GTT said:

Mine doesn’t have two plugs . It’s a 1998 rb25det Neo. I didn’t touch that sensor I removed the one in the back which is the mechanical tps which is measured by the throttle / pedal . 

 

 

TPS I bought

Yeh man what you bought is the TPS. Exactly what's circled in the picture I sent, non Neo's sometimes have 2 plugs but that doesn't change the procedure of setting the correct TPS voltage

[AndyR34GTT]

Great to hear ! Thanks 🙏  waiting for my iacv gasket to get it back together and pray it starts. I’m worried it’s clogged injectors , cam angle sensor , or block is shot . I plan to do tests on all this need week . 

[AndyR34GTT]

Problem solved 

 

Things I did , 

 

replaced fuel filter, tps sensor , air fuel meter , iacv gasket (had to since I removed it to clean it)

 

other things I did was removed spark plugs and cleaned , checked all coil packs and retighten down packs , cleaned iacv valve , hollowed out oem cat (looked super clogged), reset ecu , cleaned AFM apexi filter pod .

 

not sure what did it but I’m assuming it was either tps or air flow meter / dirty filter