Mazda Forum - Mazda Enthusiast Forums - 2008 Mazda 3 HB 2.3L Exhaust Manifold Removal

** I think I've done a pretty good job of searching for a prior post on this issue and don't think I'm duplicating anything. I don't know enough to know if the one similar thread of an older year and the 2.0L engine is applicable. I'm happy to be pointed to a prior thread if there is one that's suitable.

My granddaughter has a 2008 Mazda 3 Hatch Back with a 2.3L [non-California] engine. It started throwing a CEL due to the upstream O2 sensor. I soaked the base of the sensor with Free All (I'm an old Liquid Wrench guy but several folks said Free All was better than LW or PB Blaster) once a day for 5 days before trying to remove it. It didn't budge. I soaked it another night and then drove it until the engine was nice and hot. It still didn't budge. Then I heated the bung with a propane torch. It still didn't budge. Finally, I tried a little more leverage. Crack! The sensor broke cleanly even with the manifold bung.

My next step is to try to remove it, after several more days of soaking with Free All, using a #6 or #7 Ease-Out. At this point I'm not holding much hope that will work so I've begun investigating removing the manifold for either repair or replacement. I have the Mazda3 Workshop Service Manual and it shows a removal procedure (listed below) far more complicated than what visual examination would make me think. In fact, it looks like it would be pretty simple to remove it topside but the manual shows removing it from the bottom.

Has anyone here had any experience removing the exhaust manifold on this year, model & engine? Do I really need to follow the steps below?

Thanks in advance for whatever help/experience you can offer.

Howard
Redmond, WA
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Exhaust Manifold Removal Note
Caution • Over bending of the exhaust flexible pipe may cause damage resulting in failure.
1. Remove the front wheels and tires.
2. Disconnect the steering shaft from the steering gear and linkage side. (See 02-13-14 FRONT CROSSMEMBER REMOVAL/INSTALLATION.)
3. Remove the NO.1 engine mount rubber. (See 01-1 OA-28 ENGINE REMOVAL/INSTALLATION[LF, L3].)
4. Loosen the exhaust manifold bolts.
5. Remove the installation bolts of the front stabilizer and stabilizer contro/link. (See 02-13-11 FRONT STABILIZER REMOVAUINSTALLATION.)
6. Loosen the front crossmember component installation bolts and lower the front crossmember component approx. 100 mm {3.94 in}. (See 02-13-14 FRONT CROSSMEMBER REMOVAL/INSTALLATION.)
7. Support the flexible pipe with a support wrap or splint as shown in the figure.
8. Remove the exhaust manifold by lowering it to the underside of the vehicle.