Runs poorly without O2 sensor

[Rocinante]

Recently repaired the D/S exhaust manifold on my 2003 M45. During the removal process the secondary O2 sensor was damaged. The car now no longer wants to rev and is very sluggish while driving, almost like it's in limp mode. Would lack of an O2 sensor make the car run that poorly. Pulled two codes recently; P1119 and P0037. Seems to idle fine for 5 minutes or so, then if I go down the road, it acts as above. Any help would be greatly appreciated. Have put less the 5 miles on it in this condition so as not to damage the car.

Rocinante.

[EniGmA1987]

pretty sure the car NEEDS all the O2 sensors to properly time the engine and adjust the fuel mixture...

[EdBwoy]

P0037.^^yup! All 4 of them are needed for optimal performance. Normally during the first few moments of startup cars run with no regard for the feedback from the O2 sensor. That might explain why your idle is ok at first.
Then after the engine is warmed up, but under 3600 rpm, the sensor feedback matters. Over 3600 rpm it is turned off again.

Which might be related to....
P1119. This is your coolant temp sensor. The fsm says that if the ecm detects an issue with it, the car just assumes the coolant is 97 degrees F. In my mind I think that would also slow you down. Nissan probably doesn't want you revving the hell out of a cold engine... but I have to research a little more to verify exactly how, if it all, it affects driveability.

[Rocinante]

Thank you for the replies gentlemen. I did look up the root causes (codes) and and how they may be related. The answers that I received here are much more understandable to me. My first fix this weekend is the O2 sensor. Appreciate all your effort guys. Big thanks.

[EdBwoy]

You're welcome. I'm glad to be of some help.
On the engine temperature issue:
I don't have access to my 03 radiator, but could you please verify if the coolant temperature sensor is at the bottom of the radiator? Section-page EC-433 of the FSM says it is located there, but I only recall it being behind the bank 1/driver side head.
It is possible that the harness wasn't reconnected or the wires were tampered with when reaching for the 02 sensor as they're in the same area.

[Rocinante]

Will try to check this evening. I am working late so I will do my best. The issue with the engine temp may well have existed prior to me removing the exh. manifold. I had very little seat time in the car before purchasing it. It had a front end issue and was not roadworthy. I repaired the control arms and then started on the exhaust. I did run it for a little while in between the two repairs and it seemed fine, albeit a little noisy.

Thanks again.

[EdBwoy]

No problemo
If I may ask, what was wrong with your manifold, cracked?

[Rocinante]

Sooo... I was able to get out of work a little early. I looked for any type of sensors on the radiator tanks and did not locate any. There appears to be some small hoses coming off of the core itself...maybe. it is about to storm here so it is getting very dark and visibility is limited. Sorry, could not make out anything near the rear of the head that may be a sensor. Ok, so I bought this car because it had tapped a curb in the snow and elongated one of the holes where the control arm mounts. This in turn made the wheel somewhat crooked. Fearing the worst and not having any repair money, I was able to get it rather cheaply from the owner. I removed the offending bracket, had exact duplicate made by a race shop and welded it back in. Perfect! Knew there was an issue with the manifold so I pulled it. There is NO room to work but I was able to pull the heat shield and access the manifold. It was cracked completely around the center. Now, there is also a heat shield welded to the manifold that had to be removed with a grinder to access the entire crack. Infiniti sure did it's best to keep heat off the wire looms and out of the engine compartment. It even had asbestos behind the H/S on the manifold. It is stainless so it welded up nicely. I removed the two secondary cats (but not the O2 sensors) and had two pipes run from the manifolds to the mufflers.
New to get it running well again. Sorry for the long post. Whew!

[EdBwoy]

Sooo... I was able to get out of work a little early. I looked for any type of sensors on the radiator tanks and did not locate any. There appears to be some small hoses coming off of the core itself..

I got a chance to instal mine today and yes, there is a temp sensor on the radiator as well as on the bank 1 head. It is located at the very bottom left/driver side of the radiator and is the typical blue Nissan sensor. There should be a harness coming from under the air intake into it.

I feel you on the exhaust work part. Good thing you handled it pretty easily and it also helps that you can weld yourself. I have some ideas for mine, if only I had the time and space to play with different setups.

[Rocinante]

Hey, good to hear from you again. Wish I could take credit for the welding, but nope. It was done buy the same buddy who did the other repairs. I did grind off the heat shields to make it clean. I am hoping to tackle both the O2 sensor and possibly the temp sensor this week. Time will tell. Thanks again.Update soonest.