Strange things after new o2 Sensor?

[boosted99_420]

Ok so i got all my maintenance done on my car to start the build on it but i was wrong. I needed an o2 sensor because i just had an old one pluging the hole in the o2 housing so i went and got a brand new Bosch Direct fit OEM. I installed it and plugged it in and the next day i decided to see how it ran because it was late when i got home to work on car. It wouldnt start like it wasnt getting gas or something after a while of going WOT back and forth it finally started and after it warmed it it seems fine just the idle is still high which i am fixing as soon as i get an off day. So i tried to take it down the road to the gas station and when im driving normal not trying to kick the boost in it it starts backfireing like crazy, loses power, and falls on its face but once i hit boost it picks up and shoots off like a rocket up til about 4500 RPM then it starts backfireing real bad and fals on its face again. So i decided to unplug the o2 sensor again and it runs great just the occational stutter in boost. Heres the mods done to it.

6 Bolt swap 2g pistons 1g big rods (i belive)
FMIC w/short route piping
Port and Polished 14b
DNP Manifold
Port and Polished 6 Bolt Head
Walbro 255lph
Gutted cat and no muffer on stock pipes for now
450cc Blue tops
1g 60mm Throttle body
EGR Completely removed and blocked
Vaccume lines delted also (not sure what its called but no vaccume from throttle body)


Im not sure if these would cause it to hit Fuel Cut or what but i need this car at the top of its game when i start the build if i dont sell it now. For the money im dumping into this thing to get it just ready to run on the streets at stock boost is costing me money i am trying to save for a new car and its just pretty much putting me on the verge of ending the DSM life for a while til I graduate college in a couple years. So if anyone has any ideas of what is causing this and how to prevent it let me know ASAP.

 

[nickk90]

Weird I also got a Bosch sensor after mine went out and it sputters and bucks going into boost then around 5psi clears up and takes off.
I checked for boost leaks , new plugs and wires and none helped. I was thinking it had to be my MAF or O2 sensor now I know.

 

[luv2rallye]

Make sure you didn't connect the signal ground to chassis ground. Read the "Important note" here: http://www.dsmtuners.com/forums/articles-electrical-wiring/244376-oxygen-sensor-wiring.html.
Also make sure the other O2 wires are connected properly.

 

[MikeyTsi]

It might help to reset your ECU as well if you haven't already. Letting it re-learn everything from scratch after replacing a bad sensor may be a bit faster.

 

[nickk90]

They plug in to the factory connector. I cleared my codes. My car was burning alot of oil for a little while until I replaced my valve stem seals would the oil kill the sensor?

 

[boosted99_420]

Did reset ecu, im going to do it again soon when I get off today, I may just go ahead and order a maf and maft for it and bypass the stock one, if that don't work ill just run no front o2 I guess, its frustrating. And I didn't get the one you have to cut I got the one that is plug in and go already wired up.

 

[nickk90]

Let me know what you come up with. How can you test your MAF?

 

[hayourwifeleftu]

Something else is wrong with the car check your engine coolant temp sensor.

 

[boosted99_420]

A coolant temp sensor wont make the car run rich and backfire then pick up after boost kicss in thats in the o2, maf, intake, and even ECU. Coolant temp sensor just causes idle surge and high idle for the most part.


And i havnt had time to work on car cause of storms in my area and working almost 24/7

 

[boosting_pwr]

Mine started doing the same thing but all I had was a major boost leak. Funny how you fix something and then something else needs fixed.

 

[luv2rallye]

A coolant temp sensor wont make the car run rich

Actually a non-functioning CTS (ECU one - not the gauge one) will fool the ECU into thinking the engine is always cold so it will richin the mixture.

 

[nickk90]

I checked my coolant temp sensor before I replaced my o2 senor. Only boost leak I have is a small leak at the BOSS screw not big enough to chase problems. It only happens once I the car warms up and on part throttle so it leads me to believe its a closed loop problem. Since me and OP have the exact same problem I have a feeling its the Bosch sensor.

 

[boosted99_420]

Im just gonna sell the POS DSM are more trouble than they are worth im not dumping any more money into a car that's not worth 3k so im done with them, V8s here I come.

 

[hayourwifeleftu]

Actually a non-functioning CTS (ECU one - not the gauge one) will fool the ECU into thinking the engine is always cold so it will richin the mixture.

Exactly and the fact the car didn't start when it was cold made me guess the coolant temp sensor.