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Rear diffuser removal- can it be this difficult? / P0171

11K views 86 replies 13 participants last post by  Sslawson  
#1 ·
I have a 07 Exige S and I’m trying to remove the rear diffuser to get at the 02 sensors. I removed all 14 bolts and it’s loose but won’t come off.
What am I missing???
Thanks for any help

Image
 
#6 ·
owns 2006 Lotus Elise
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#11 ·
I almost always remove the engine pan before the diffuser. It’s rare that I don’t need both out of the way, and when removing both it’s easier to remove the engine pan first.

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Since I always need both off anyway I take both off as one unit. Yes, I never take off the 5 bolts holding them together.

Also, I unbolt everything with the car on the ground no problem. Then when I lift the first side, I pull the whole thing out the back.
 
#13 ·
When I drop my belly pan's it's onto a HF dolly with a 2" foam board on top it's slides out easily then and also allows cantilevering the belly pan into the slot easily with one hand.
 
owns 2006 Lotus Elise
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#16 ·
One option

 
owns 2006 Lotus Elise
#17 ·
Ahh yes monkey wrench racing , I’ve seen their name a fair amount on this site.
Thanks for teeing this up so I can order tomorrow!
ive been working on this PO171 code since about a week into acquiring my Lotus and I am itching for some long drives without staring at an engine check light!
 
#18 ·
If still having issues after replacing o2 sensors check for vacuum leaks and see if MAF dirty again.
 
owns 2006 Lotus Elise
#19 ·
Also get your battery checked. I had a P0171 that stayed no matter what. Did o2 sensors, propane checked for leaks, cleaned my MAF. Nothing would make it go away. Just threw a new battery at it and BAM all fixed up.
 
#20 ·
Never a bad idea to have battery load tested for intermittent and weird issues.
 
owns 2006 Lotus Elise
#29 ·
Please start a seperate thread for yours so all the advice doesn't start cross threading. Here's a thread for you
 
owns 2006 Lotus Elise
#28 ·
Thanks again for the tips. So to recap, I have replaced the MAF, made sure my gas cap is on and tight, the 02 sensors from monkey wrench racing are on order and will go in when I receive them. I am charging the battery (a small light weight one the seller said was fairly new but I'll check my receipts) then place on trickle charge.
Then off for a test ride.
If CEL comes up again I'll spray some starter fluid around the intake to hear for any vacuum leaks (should have done this first!) and have the battery checked. Only thing I can think of after that is fuel pump or/injectors (I've been running 91 Shell and STP injector cleaner).
I will also keep track of the mileage. I only had it for a week before the CEL so I don't have a lot of info, but I will pay close attention to see if the fuel mileage is normal- 25-28 MPG
 
#30 ·
New or old the only true test of the battery once you fully charge it is a load test. It's free so a no brainer.
 
owns 2006 Lotus Elise
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#32 ·
Ok here’s the update. I replaced the 02 sensors (both pre and post cat), clears the code and drove it for 50 miles and no CEL. Usually I’d clear the code and within 10 miles it would pop up again- so something has changed. I’ll continue to drive and let folks Know how it goes.
Thanks again for all the help LT!!
 
#33 ·
i Took another short drive this morning and the CEL came back on....
Did I read somewhere on this forum that after fixing an issue and clearing all stored codes that a code will/can sometimes take a while for the ECU to get used to the change and not thro a code?

should I disconnect the battery and touch the negative positive end together to drain all charges in the system?

here we go again...
 
#34 ·
i Took another short drive this morning and the CEL came back on....
Did I read somewhere on this forum that after fixing an issue and clearing all stored codes that a code will/can sometimes take a while for the ECU to get used to the change and not thro a code?

should I disconnect the battery and touch the negative positive end together to drain all charges in the system?

here we go again...
Did you get your battery load tested?
 
#37 ·
You might want to see if you can get an AFR reading on the vehicle. Most exhausts dont require a tune. Check for vacuum leaks, besides the exhaust, what else has been changed on this vehicle?
 
#39 ·
You might need a O2 extender to prevent the codes. What code are you getting?
 
owns 2006 Lotus Elise