Question about 2002 Toyota MR2 Spyder

1 Answer

Rich fuel mixture banks 1&2

2002 MR2 fuel system too rich bank 1 and bank 2 Check engine light was on and dealer diagnosed the problem as needing to replace all 3 oxygen sensors. I replaced all 3 sensors and now I am getting p0172 and p0175 codes. LTFT for both banks was at -42%. I reset the codes and also disconnected the battery to reset the LTFT to 0%. Drove the car about 30 miles and the MIL light came on again showing the same 2 codes. If I was sold the wrong oxygen sensors could that cause this problem? Peter. The dealer did diagnose the problem. They said the car needed all 3 oxygen sensors replaced. They were replaced and the car is now returning codes p0172 and p0175 which are the only 2 codes coming up when the check engine light came on. My question is if the dealer sold me the incorrect oxygen sensors could this cause the computer to incorrectly set the p0172 and p0175 rich fuel mixture codes. There are no other codes coming up. My plan at this point is to check and clean the MAF, check my fuel pressure, and also the TPS but I did not want to waste my time if it could possibly be that the new oxygen sensors where the problem. Any help would be appreciated.

Posted by on

  • 2 more comments 
  • Tim Dankert Jan 24, 2013

    Car has approximately 50000 miles. Car does have slight hesitation when you snap the throttle.

  • Tim Dankert Jan 24, 2013

    When you snap the throttle engine stumbles slightly then revs up normally.

  • Tim Dankert Jan 24, 2013

    I cleaned the MAF and the hesitation is gone and the fuel trims are now reporting within the normal range.

  • Tim Dankert Jan 24, 2013

    If problem returns I will probably replace the MAF. Thanks to everyone that offered a possible solution.

×

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

  • Toyota Master
  • 42,863 Answers

Fuel sensors work in the hottest part of the exhaust and are difficult to remove after a period of time. Many mechanics apply a small amount of never seize to the threads to assist in replacement and future removal. However this affects the grounding of the sensor and can cause fault readings. Ask the mechanic if he did that and follow you idea that the sensors may aftermarket and not suitable for yoyr car

Posted on Jan 23, 2013

  • Tim Dankert Jan 24, 2013

    Thanks for the info. I believe I have it narrowed down to the MAF. I cleaned the MAF and the fuel trims now appear to be operating in the normal range. There are now in the +/- 3-4% range.

×

Ad

3 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Ad
  • 1243 Answers

SOURCE: problem was diagnosed as the

yes the O2 heater in the sensor will make the CEL come on because the computer is not receiving proper signal from the sensor.

Posted on Jul 14, 2011

  • 6 Answers

SOURCE: Check Engine Light Toyota Corolla

What is the mileage on that car? If the MAF sensor would be acting up, you get tip in acceleration hesitation, it sounds like the Air bypass valve is having issues. Replace it. Do not clean it just replace it.

Posted on Aug 29, 2011

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Engine light on


P0171 ; Fuel Trim System Lean (Bank 1)
P0174; Fuel Trim too Lean (Bank 2)
fuel trim is system to modify injector pulse if system go lean it will go rich when the system is too much lean and is max.rich it code
look for 02 sensor bank 1 and 2 data
hope it helps

Mar 31, 2014 | 2003 Chevrolet Malibu

1 Answer

Suburban service engine soon


i think the check engine light caused by oxygen sensors,due to little misfire detected , fuel system ,bank 1 and bank 2 lean and rich mixtures..

Sep 25, 2013 | 2002 Chevrolet Suburban

1 Answer

System lean bank 1 p0172 fuel


PO 171 Bank 1 too lean
PO 174 Bank 2 too lean
Why ?
The front O2 Sensors need to be replaced at
100,000 miles or sooner, if they have actually failed
They are reading too lean because the system is too
rich & the computer is driving the fuel trim or injector
pulse lean, thus the codes or failed sensors, yes both
Have to check fuel trim with a scan tool
Have to check fuel pressure
Have to check there are no leaking injectors
Have to check for Vacuum Leaks from the intake
all the way to the exhaust converter
Your working a rich condition keeping in mind the system
is driven lean
You look at fuel trim short & long,sort of a past history
of events
May want to look at converter temps also
The converters won't last long if you have or has
a rich condition from fuel or cylinder misfires
Now the spark plugs can't be over 3 years old
& no mifires,get that out of the way before working
the O2 issues

Jul 27, 2013 | 2005 Mitsubishi Endeavor

1 Answer

2002 MR2 fuel system too rich bank 1 and bank 2


Peter. The dealer did diagnose the problem. They said the car needed all 3 oxygen sensors replaced. They were replaced and the car is now returning codes p0172 and p0175 which are the only 2 codes coming up when the check engine light came on. My question is if the dealer sold me the incorrect oxygen sensors could this cause the computer to incorrectly set the p0172 and p0175 rich fuel mixture codes. There are no other codes coming up. My plan at this point is to check and clean the MAF, check my fuel pressure, and also the TPS but I did not want to waste my time if it could possibly be that the new oxygen sensors where the problem. Any help would be appreciated.

Jan 21, 2013 | 2002 Toyota MR2 Spyder

1 Answer

I need to know which O2 sensors are which: Bank 1 Sensor 1, Bank 1 Sensor 2, Bank 2 Sensor 1, and Bank 2 Sensor 2. Which are on the engine block and which are on the exhaust?


bank one upstream oxygen sensor on exhaust manifold bank two oxygen sensor after catalytic converter.tell me what code you are getting.bank 1 sensor 1 fuel system is too rich fuel pressure too high fuel pressure regulator leaking or more than 1 fuel injector leaking. fuel contaminated.check spark plugs if black carbon color fuel system too rich. if you getting code bank 1 sensor 2 check for air leaks in the exhaust system, air leaks intake manifold.look for vacuum lines leaks,look for vacuum leaks pcv valve and hose and make egr valve not stuck open or gasket leak.

Apr 15, 2011 | 2003 Mazda MPV

1 Answer

Check engine light is on - 3 codes 17748,17573,17755. Fuel mileage is down significantly, as is engine power


17748 camshaft sensor and crankshaft sensor incorrect correlation [bank 1]. Valve timing is most probably incorrectly set. 17573 Rich mixture. Can be caused by high fuel pressure. -Faulty Lambda Probes. - Blockage in exhaust system[ loose baffles] - Blockage in inlet[clogged air filter] Petrol tank breather system [faulty canister purge valve]. 17755 same as 17748 but bank two. Check valve timing, Fuel pressure and for loose baffles in exhaust system.

Jun 02, 2010 | 2002 Volkswagen Eurovan

1 Answer

Speedometer sudenly stoppped working. now works intermittently. also shows check engine light. It is showing p0171 & p0172 codes. Lean and rich. seams like they contradict each other. occasionaly the...


P0171 indicates a lean condition. The most common cause of this is a defective mass air flow sensor. Also check if any vacuum leaks.Replace MAf sensor,if cleaning the MAF does not help.
OBD II P0172 Fuel System Too Rich (Bank 1).P0172 - System Too Rich (Bank 1) Essentially this DTC means that an oxygen sensor in bank 1 detected a rich condition.
When the code says that the Fuel System is "too rich," it means that the computer has been subtracting more and more fuel, which is called Long Term Fuel Trim. Ideally, the Long Term Fuel Trim should be close to 1 to 2 percent. When a code P0172 is set, it means that the Fuel Trim is anywhere from -15 percent to as low as -30 percent compensated. When this happens, the computer knows that there is an improper condition in the control of the Fuel System.


Thanks.

Feb 07, 2010 | 1996 Volvo 850

3 Answers

Check engine light (emission system service required) Help?!?!


There may be problem with the mass air flow sensor (very common with Volvo). This causes the fuel system to malfunction.

You may have noticed increased fuel consumption, loss of power and general 'lazyness'.

Better to take it to authorized Volvo service for a checkup/fix.

Jan 13, 2010 | 2000 Volvo S80

4 Answers

Check Engine light is on my 1997 F150 with a small V-8. The tester returns codes P0171, P0172, P0174 and P0175. What does all this mean?


those codes are for lean engine condition look for vac leaks at the back of engine to the pcv valve could hear hissing noise with engine running also check egr valve to be stuck open also when was last fuel filter changed? hope this helps .

Sep 16, 2009 | 1997 Ford F150 Regular Cab

1 Answer

20 mpg down to 11 mpg !


Replace your bank 1 (that's the cylinder bank with cylinder #1 in it, usually passenger side but verify this before changing parts) primary oxygen sensor. This is the one before the catalytic converter. The primary determines your air/fuel mixture, and if it goes bad, the computer will revert to preprogrammed fueling maps, which are fuel-rich by design (to safeguard the engine). Change the O2 sensor on bank one, before the cat, and maybe check your spark plugs as well (running rich too long will foul them) - for the minimal cost, it's worth changing them too.

Aug 29, 2008 | 1996 Plymouth Grand Voyager

Not finding what you are looking for?
2002 Toyota MR2 Spyder Logo

566 people viewed this question

Ask a Question

Usually answered in minutes!

Top Toyota Experts

yadayada
yadayada

Level 3 Expert

76164 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8274 Answers

Are you a Toyota Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...