So I got my headman shorties, y pipe, with offroad pipe in place of cat and magnaflow catback installed this weekend. Turns out that my knock sensor was broken at the connector to the pig tail. Problem again is that with the headers there isnt enough room to plug the new pigtail into the new knock sensor, so they left it unplugged. they also unpluged my O2 sesor since the headers didnt have an O2 bung pre drilled. I figure I can drill my own O2 bung and probably do something about the knock sensor, but for now the car is driving amazing. I do get a check engine light but only when I'm in overdrive. If I leave the car in the D only position I never see the light. How bad would it be If I left it the way it is for a while?

ps- this is all on a 91 350 tpi, no a.i.r., no ac, 100% stock engine except for the exhaust.

 

id think without the knock sensor plugged up something bad could happen and you wouldnt know until its too late. if the knock sensor detects something it will tell the ecm to go into whats called "limp home mode" which makes the car protect itself by basically running like crap so it wont hurt itself even more. if i were you id make a point to get both sensors put in as soon as you could especially now that you will (im sure) be driving it a little harder with your new exhaust

 

No knock sensor = no power via limp mode
No way the car drives "Amazing"

Regardless, it is a common problem not to have room for the knock sensor in the factory location
Luckily there is another bung conveniently on the drivers side of the block in nearly the same area
If that doesnt fit either, drill and tap a hole in the fuel pump block-off plate and mount it there

You can mount a new O2 bung anywhere you find room
I would suggest a common 3 wire heated O2

 

[quote=Pocket;3821171]

No knock sensor = no power via limp mode
No way the car drives "Amazing" [quote=Pocket;3821171]
the car drives fine, unless im mistaken and that isnt the knock sensor on the rear passenger side of the block...