Anybody have any ideas? The rear one doesn't affect the air/fuel right? Can a bad cat cause me to run rich?

Thanks!!

 

i think..... notice its i think... a bad map sensor can do that but i may be wrong.. i dont totally understand the map sensor

but i just wanted to give u something to run with incase no1 answered

 

Yeah, I read that it can cause that..but I still get good gas mileage..and no black smoke???? Any ideas? How can I check if it is a bad? Also, I currently have a Too Rich (Bank 1) code..can a bad map sensor cause that? Oh and my plugs are no where near brown or black! Oh and can a rear O2 sensor make me run rich? The rear one doesn't affect air/fuel ratio..right?

Thanks!!

 

Anybody know if I buy a chipped ECU and have it dyno tuned..if this will fix my problem? Or would I still need a new CAT.

Thanks!!

 

Bump for some help..please help..I need to know if the wiring might be causing my rich condition..anyone know how to check?

 

put on a test pipe. at first i would blow out white/black smoke, but after i put on the test pipe a giant cloud of black smoke pops out when i downshift into vtec.

 

if you dont have a thermostate you will run rich, o2's that going bad or are bad will make you run rich,

 

I read a few of your posts and you mentioned something about a FPR. How long have you had that on your car? That might be the problem. There is alot of things that can make your car run rich. Are there anymore codes other than system to rich? If you had a bad MAP or TPS out of calibration it will make your GSR run to rich, but it will also set codes for MAP or TPS. Bank 1 O2 sensor sees how much air/fuel is burned after combustion(exhaust content), Bank 2 sees how efficient your cat is working. If you have only a Bank1 code system to rich, I'll go back to the factory FPR and check the fuel pressure. I don't have the specs. for fuel pressure on top of my head, but check the repair manual.

 

My FPR is set at 36 psi..which is stock according to my manual and other related threads on here...so that shouldn't affect me running rich..right? Nope..I have no other codes..just Too Rich (Bank 1) Catalyst Efficiency Below Threshold (Bank 1) and Fuel Trim Malfunction...I am going to replace my cat with a universal one eventually..but would rather fix my running rich problem first..what I don't get is my spark plugs are still a little greyish..no where near black..but my car says I am running rich..and I didn't notice a little change in my miles per gallon..

Thanks eveyone for all the help!

 

Anyone know how to check and replace the wiring of an O2 sensor?..or does anyone have a write up with pictures on replacing my rear O2 with a universal one..?

Thanks!

 

If you want to check the O2 sensor, there's two ways to do it. 1- check it with a scan tool. Connect a scantool to the OBD-2 connector and check the activity, the voltage should fluccate .5-5 volts. 2- if you don't have a scan tool use a voltmeter, probe red to positive and ground the voltmeter and check to voltage activity. Same deal, voltage should fluctuate .5-5 volts. If you want to replace it with a universal one. AutoZone has one with a wire schematic, they run about $30.00. I replaced a four wire one in my 95' GSR not to long ago.

 

Brief exaplaintion of engine management and what could possibly cause your code:
1) Fuel injection mapping is stored in the ECU.
2) It uses a bunch of sensors to determine engine load (map sensor, TPS, etc) and injects the correct amount of fuel (according to the map) using injector duty cycle (open time for fuel to flow) for a given load and engine rpm.
3) The O2 sensor feeds back to the ECU how well the mixture is being burnt, if lean it will inject more fuel and conversely if rich will take away fuel. This is known as Fuel Trim.
4) There is a certain range of Fuel Trim that is deemed acceptable and if you exceed it will set a too rich or too lean code.

Your ECU is seeing trying to take away fuel but has reached the set code threshold. What could be causing the problem. I would look at the aftermarket fuel pressure regulator. The fuel pressure should be checked at both idle (full vacuum) and simulating wide open throttle (pulling off the vacuum hose). Check this before replacing sensors. I suspect that your fuel pressure is too high, double check with a known good gauge.j